{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-66884", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-07-28T04:15:10.240Z", "datePublished": "2026-08-04T11:45:49.464Z", "dateUpdated": "2026-08-04T12:40:41.232Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:erlef:oidcc_plug:*:*:*:*:*:erlang:*:*"], "defaultStatus": "unaffected", "modules": ["Elixir.Oidcc.Plug.AuthorizationCallback"], "packageName": "oidcc_plug", "packageURL": "pkg:hex/oidcc_plug", "product": "oidcc_plug", "programFiles": ["lib/oidcc/plug/authorization_callback.ex"], "programRoutines": [{"name": "'Elixir.Oidcc.Plug.AuthorizationCallback':call/2"}], "repo": "https://github.com/erlef/oidcc_plug", "vendor": "Erlang Ecosystem Foundation", "versions": [{"lessThan": "0.5.0", "status": "affected", "version": "0.2.0-beta.1", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:erlef:oidcc_plug:*:*:*:*:*:erlang:*:*"], "defaultStatus": "unaffected", "modules": ["Elixir.Oidcc.Plug.AuthorizationCallback"], "packageName": "erlef/oidcc_plug", "packageURL": "pkg:github/erlef/oidcc_plug", "product": "oidcc_plug", "programFiles": ["lib/oidcc/plug/authorization_callback.ex"], "programRoutines": [{"name": "'Elixir.Oidcc.Plug.AuthorizationCallback':call/2"}], "repo": "https://github.com/erlef/oidcc_plug", "vendor": "Erlang Ecosystem Foundation", "versions": [{"lessThan": "97d75afc57826dca31989b47d6e2a3c136039917", "status": "affected", "version": "e577ae73b9080693442916043a22d8f05491dd93", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:erlef:oidcc_plug:*:*:*:*:*:erlang:*:*", "versionEndExcluding": "0.5.0", "versionStartIncluding": "0.2.0-beta.1", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Mathias Polligkeit"}, {"lang": "en", "type": "remediation developer", "value": "Mathias Polligkeit"}, {"lang": "en", "type": "remediation reviewer", "value": "Jonatan M\u00e4nnchen / EEF"}, {"lang": "en", "type": "coordinator", "value": "Jonatan M\u00e4nnchen / EEF"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (<code>Oidcc.Plug.AuthorizationCallback</code> module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated.</p>\n<p>This vulnerability is associated with program file <code>lib/oidcc/plug/authorization_callback.ex</code> and program routine <code>Oidcc.Plug.AuthorizationCallback.call/2</code>.</p>\n<p>A callback request that carries no <code>Oidcc.Plug.Authorize</code> session is processed with every security check disabled rather than being rejected. <code>call/2</code> substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns <code>:ok</code>, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of <code>check_state/2</code> also accepts a state-less request when a verifier is present.</p>\n<p>An attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no <code>state</code> parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's.</p>\n<p>The permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. <code>Oidcc.Plug.Authorize</code> always sends a <code>state</code> parameter, which an authorization server must echo, so no legitimate callback lacks one.</p>\n<p>This issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0.</p>"}, {"base64": false, "type": "text/markdown", "value": "Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (`Oidcc.Plug.AuthorizationCallback` module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated.\n\nThis vulnerability is associated with program file `lib/oidcc/plug/authorization_callback.ex` and program routine `Oidcc.Plug.AuthorizationCallback.call/2`.\n\nA callback request that carries no `Oidcc.Plug.Authorize` session is processed with every security check disabled rather than being rejected. `call/2` substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns `:ok`, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of `check_state/2` also accepts a state-less request when a verifier is present.\n\nAn attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no `state` parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's.\n\nThe permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. `Oidcc.Plug.Authorize` always sends a `state` parameter, which an authorization server must echo, so no legitimate callback lacks one.\n\nThis issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0."}], "value": "Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (Oidcc.Plug.AuthorizationCallback module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated.\n\nThis vulnerability is associated with program file lib/oidcc/plug/authorization_callback.ex and program routine Oidcc.Plug.AuthorizationCallback.call/2.\n\nA callback request that carries no Oidcc.Plug.Authorize session is processed with every security check disabled rather than being rejected. call/2 substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns :ok, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of check_state/2 also accepts a state-less request when a verifier is present.\n\nAn attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no state parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's.\n\nThe permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. Oidcc.Plug.Authorize always sends a state parameter, which an authorization server must echo, so no legitimate callback lacks one.\n\nThis issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0."}], "impacts": [{"capecId": "CAPEC-62", "descriptions": [{"lang": "en", "value": "CAPEC-62 Cross Site Request Forgery"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 2.1, "baseSeverity": "LOW", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-352", "description": "CWE-352 Cross-Site Request Forgery (CSRF)", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-08-04T11:45:49.464Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/erlef/oidcc_plug/security/advisories/GHSA-fg66-w5gp-22cr"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-66884.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-66884"}, {"tags": ["patch"], "url": "https://github.com/erlef/oidcc_plug/commit/97d75afc57826dca31989b47d6e2a3c136039917"}], "source": {"discovery": "EXTERNAL"}, "title": "Oidcc.Plug.AuthorizationCallback accepts callbacks with no authorize session or no state parameter, defeating CSRF protection", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Insert a plug before <code>Oidcc.Plug.AuthorizationCallback</code> that rejects the request when either the <code>Oidcc.Plug.Authorize</code> session or the <code>state</code> query parameter is missing. This restores the binding the callback fails to enforce and does not require modifying the library.</p>"}, {"base64": false, "type": "text/markdown", "value": "Insert a plug before `Oidcc.Plug.AuthorizationCallback` that rejects the request when either the `Oidcc.Plug.Authorize` session or the `state` query parameter is missing. This restores the binding the callback fails to enforce and does not require modifying the library."}], "value": "Insert a plug before Oidcc.Plug.AuthorizationCallback that rejects the request when either the Oidcc.Plug.Authorize session or the state query parameter is missing. This restores the binding the callback fails to enforce and does not require modifying the library."}]}, "adp": [{"references": [{"url": "https://github.com/erlef/oidcc_plug/security/advisories/GHSA-fg66-w5gp-22cr", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-04T12:37:09.321822Z", "id": "CVE-2026-66884", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-04T12:40:41.232Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-66884", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-04T12:37:09.321822Z"}}}], "references": [{"url": "https://github.com/erlef/oidcc_plug/security/advisories/GHSA-fg66-w5gp-22cr", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-04T12:40:37.053Z"}}], "cna": {"title": "Oidcc.Plug.AuthorizationCallback accepts callbacks with no authorize session or no state parameter, defeating CSRF protection", "source": {"discovery": "EXTERNAL"}, "credits": [{"lang": "en", "type": "finder", "value": "Mathias Polligkeit"}, {"lang": "en", "type": "remediation developer", "value": "Mathias Polligkeit"}, {"lang": "en", "type": "remediation reviewer", "value": "Jonatan M\u00e4nnchen / EEF"}, {"lang": "en", "type": "coordinator", "value": "Jonatan M\u00e4nnchen / EEF"}], "impacts": [{"capecId": "CAPEC-62", "descriptions": [{"lang": "en", "value": "CAPEC-62 Cross Site Request Forgery"}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 2.1, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "LOW", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N", "providerUrgency": "NOT_DEFINED", "userInteraction": "ACTIVE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "affected": [{"cpes": ["cpe:2.3:a:erlef:oidcc_plug:*:*:*:*:*:erlang:*:*"], "repo": "https://github.com/erlef/oidcc_plug", "vendor": "Erlang Ecosystem Foundation", "modules": ["Elixir.Oidcc.Plug.AuthorizationCallback"], "product": "oidcc_plug", "versions": [{"status": "affected", "version": "0.2.0-beta.1", "lessThan": "0.5.0", "versionType": "semver"}], "packageURL": "pkg:hex/oidcc_plug", "packageName": "oidcc_plug", "programFiles": ["lib/oidcc/plug/authorization_callback.ex"], "collectionURL": "https://repo.hex.pm", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.Oidcc.Plug.AuthorizationCallback':call/2"}]}, {"cpes": ["cpe:2.3:a:erlef:oidcc_plug:*:*:*:*:*:erlang:*:*"], "repo": "https://github.com/erlef/oidcc_plug", "vendor": "Erlang Ecosystem Foundation", "modules": ["Elixir.Oidcc.Plug.AuthorizationCallback"], "product": "oidcc_plug", "versions": [{"status": "affected", "version": "e577ae73b9080693442916043a22d8f05491dd93", "lessThan": "97d75afc57826dca31989b47d6e2a3c136039917", "versionType": "git"}], "packageURL": "pkg:github/erlef/oidcc_plug", "packageName": "erlef/oidcc_plug", "programFiles": ["lib/oidcc/plug/authorization_callback.ex"], "collectionURL": "https://github.com", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.Oidcc.Plug.AuthorizationCallback':call/2"}]}], "references": [{"url": "https://github.com/erlef/oidcc_plug/security/advisories/GHSA-fg66-w5gp-22cr", "tags": ["vendor-advisory", "related"]}, {"url": "https://cna.erlef.org/cves/CVE-2026-66884.html", "tags": ["related"]}, {"url": "https://osv.dev/vulnerability/EEF-CVE-2026-66884", "tags": ["related"]}, {"url": "https://github.com/erlef/oidcc_plug/commit/97d75afc57826dca31989b47d6e2a3c136039917", "tags": ["patch"]}], "workarounds": [{"lang": "en", "value": "Insert a plug before Oidcc.Plug.AuthorizationCallback that rejects the request when either the Oidcc.Plug.Authorize session or the state query parameter is missing. This restores the binding the callback fails to enforce and does not require modifying the library.", "supportingMedia": [{"type": "text/html", "value": "<p>Insert a plug before <code>Oidcc.Plug.AuthorizationCallback</code> that rejects the request when either the <code>Oidcc.Plug.Authorize</code> session or the <code>state</code> query parameter is missing. This restores the binding the callback fails to enforce and does not require modifying the library.</p>", "base64": false}, {"type": "text/markdown", "value": "Insert a plug before `Oidcc.Plug.AuthorizationCallback` that rejects the request when either the `Oidcc.Plug.Authorize` session or the `state` query parameter is missing. This restores the binding the callback fails to enforce and does not require modifying the library.", "base64": false}]}], "descriptions": [{"lang": "en", "value": "Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (Oidcc.Plug.AuthorizationCallback module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated.\n\nThis vulnerability is associated with program file lib/oidcc/plug/authorization_callback.ex and program routine Oidcc.Plug.AuthorizationCallback.call/2.\n\nA callback request that carries no Oidcc.Plug.Authorize session is processed with every security check disabled rather than being rejected. call/2 substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns :ok, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of check_state/2 also accepts a state-less request when a verifier is present.\n\nAn attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no state parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's.\n\nThe permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. Oidcc.Plug.Authorize always sends a state parameter, which an authorization server must echo, so no legitimate callback lacks one.\n\nThis issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0.", "supportingMedia": [{"type": "text/html", "value": "<p>Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (<code>Oidcc.Plug.AuthorizationCallback</code> module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated.</p>\n<p>This vulnerability is associated with program file <code>lib/oidcc/plug/authorization_callback.ex</code> and program routine <code>Oidcc.Plug.AuthorizationCallback.call/2</code>.</p>\n<p>A callback request that carries no <code>Oidcc.Plug.Authorize</code> session is processed with every security check disabled rather than being rejected. <code>call/2</code> substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns <code>:ok</code>, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of <code>check_state/2</code> also accepts a state-less request when a verifier is present.</p>\n<p>An attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no <code>state</code> parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's.</p>\n<p>The permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. <code>Oidcc.Plug.Authorize</code> always sends a <code>state</code> parameter, which an authorization server must echo, so no legitimate callback lacks one.</p>\n<p>This issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0.</p>", "base64": false}, {"type": "text/markdown", "value": "Cross-Site Request Forgery vulnerability in Erlang Ecosystem Foundation oidcc_plug (`Oidcc.Plug.AuthorizationCallback` module) allows an attacker to make a victim's browser complete an authorization flow the victim never initiated.\n\nThis vulnerability is associated with program file `lib/oidcc/plug/authorization_callback.ex` and program routine `Oidcc.Plug.AuthorizationCallback.call/2`.\n\nA callback request that carries no `Oidcc.Plug.Authorize` session is processed with every security check disabled rather than being rejected. `call/2` substitutes permissive defaults for the absent session, and each downstream check treats its value as nothing to compare and returns `:ok`, so the nonce, state, PKCE, peer IP and user agent checks are all skipped. A separate clause of `check_state/2` also accepts a state-less request when a verifier is present.\n\nAn attacker obtains an authorization code for their own provider account, then induces the victim to visit the callback endpoint with that code and no `state` parameter. The application signs the victim in as the attacker, so the victim's subsequent actions occur in the attacker's account where the attacker can read them. Applications reusing one callback for both signing in and linking a provider account are further exposed to account takeover, the attacker's account becoming linked to the victim's.\n\nThe permissive fallback serves no conforming flow. Third-party-initiated login reaches a relying party at a separate login initiation endpoint and causes it to send a fresh authentication request, and this library implements no such endpoint. `Oidcc.Plug.Authorize` always sends a `state` parameter, which an authorization server must echo, so no legitimate callback lacks one.\n\nThis issue affects oidcc_plug: from 0.2.0-beta.1 before 0.5.0.", "base64": false}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-352", "description": "CWE-352 Cross-Site Request Forgery (CSRF)"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:erlef:oidcc_plug:*:*:*:*:*:erlang:*:*", "vulnerable": true, "versionEndExcluding": "0.5.0", "versionStartIncluding": "0.2.0-beta.1"}], "operator": "OR"}], "operator": "AND"}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-08-04T11:45:49.464Z"}}}, "cveMetadata": {"cveId": "CVE-2026-66884", "state": "PUBLISHED", "dateUpdated": "2026-08-04T12:40:41.232Z", "dateReserved": "2026-07-28T04:15:10.240Z", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "datePublished": "2026-08-04T11:45:49.464Z", "assignerShortName": "EEF"}, "dataVersion": "5.2"}

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