{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-27590", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-02-20T17:40:28.450Z", "datePublished": "2026-02-24T16:33:41.353Z", "dateUpdated": "2026-02-24T16:33:41.353Z"}, "containers": {"cna": {"title": "Caddy: Unicode case-folding length expansion causes incorrect split_path index (SCRIPT_NAME/PATH_INFO confusion) in FastCGI transport", "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "lang": "en", "description": "CWE-20: Improper Input Validation", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-180", "lang": "en", "description": "CWE-180: Incorrect Behavior Order: Validate Before Canonicalize", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.9, "baseSeverity": "HIGH", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P", "version": "4.0"}}], "references": [{"name": "https://github.com/caddyserver/caddy/security/advisories/GHSA-5r3v-vc8m-m96g", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/caddyserver/caddy/security/advisories/GHSA-5r3v-vc8m-m96g"}, {"name": "https://github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38", "tags": ["x_refsource_MISC"], "url": "https://github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38"}, {"name": "https://github.com/caddyserver/caddy/releases/tag/v2.11.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/caddyserver/caddy/releases/tag/v2.11.1"}], "affected": [{"vendor": "caddyserver", "product": "caddy", "versions": [{"version": "< 2.11.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-02-24T16:33:41.353Z"}, "descriptions": [{"lang": "en", "value": "Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's FastCGI path splitting logic computes the split index on a lowercased copy of the request path and then uses that byte index to slice the original path. This is unsafe for Unicode because `strings.ToLower()` can change UTF-8 byte length for some characters. As a result, Caddy can derive an incorrect `SCRIPT_NAME`/`SCRIPT_FILENAME` and `PATH_INFO`, potentially causing a request that contains `.php` to execute a different on-disk file than intended (path confusion). In setups where an attacker can control file contents (e.g., upload features), this can lead to unintended PHP execution of non-.php files (potential RCE depending on deployment). Version 2.11.1 fixes the issue."}], "source": {"advisory": "GHSA-5r3v-vc8m-m96g", "discovery": "UNKNOWN"}}}}

{}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*", "matchCriteriaId": "9AD1B432-AFA3-4A05-A687-F6092CDB6498", "versionEndExcluding": "2.11.1", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's FastCGI path splitting logic computes the split index on a lowercased copy of the request path and then uses that byte index to slice the original path. This is unsafe for Unicode because `strings.ToLower()` can change UTF-8 byte length for some characters. As a result, Caddy can derive an incorrect `SCRIPT_NAME`/`SCRIPT_FILENAME` and `PATH_INFO`, potentially causing a request that contains `.php` to execute a different on-disk file than intended (path confusion). In setups where an attacker can control file contents (e.g., upload features), this can lead to unintended PHP execution of non-.php files (potential RCE depending on deployment). Version 2.11.1 fixes the issue."}], "id": "CVE-2026-27590", "lastModified": "2026-02-25T17:07:09.600", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.9, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "PROOF_OF_CONCEPT", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-02-24T17:29:04.493", "references": [{"source": "security-advisories@github.com", "tags": ["Release Notes"], "url": "https://github.com/caddyserver/caddy/releases/tag/v2.11.1"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/caddyserver/caddy/security/advisories/GHSA-5r3v-vc8m-m96g"}, {"source": "security-advisories@github.com", "tags": ["Third Party Advisory"], "url": "https://github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-180"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}