{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-129126", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-11-13T16:01:01.879Z", "datePublished": "2026-11-13T16:23:41.944Z", "dateUpdated": "2026-11-13T16:23:41.944Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-11-13T16:23:41.944Z"}, "datePublic": "2026-10-31T00:00:00.000Z", "title": "C-Kermit before 11.1.515 Heap Buffer Overflow via putsrv() Packet Decoding", "descriptions": [{"lang": "en", "value": "C-Kermit before 11.1.515 contains a heap buffer overflow vulnerability in putsrv() in ckcfns.c that allows malicious peers to write past the srvcmd buffer by sending crafted packets. Attackers can use Kermit repeat-count compression in server command, GET, or file-header packets to write attacker-chosen bytes beyond the heap buffer on servers or receiving instances."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Heap-based Buffer Overflow", "cweId": "CWE-122", "type": "CWE"}]}], "affected": [{"vendor": "OpenKermit", "product": "C-Kermit", "defaultStatus": "unaffected", "versions": [{"version": "0", "status": "affected", "lessThan": "11.1.515", "versionType": "semver"}], "packageURL": "pkg:github/OpenKermit/ckermit"}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 9.2, "baseSeverity": "CRITICAL"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p", "tags": ["vendor-advisory"], "name": "GitHub Security Advisory (GHSA-c5px-7h4c-gj8p)"}, {"url": "https://github.com/OpenKermit/ckermit/commit/37e54720779237897bc6887efac42fe138817897", "tags": ["patch"]}, {"url": "https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515", "tags": ["release-notes"], "name": "C-Kermit v11.1.515 Release Notes"}, {"url": "https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcfns.c#L461", "tags": ["technical-description"]}, {"name": "VulnCheck Advisory: C-Kermit before 11.1.515 Heap Buffer Overflow via putsrv() Packet Decoding", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-heap-buffer-overflow-via-putsrv-packet-decoding"}], "credits": [{"lang": "en", "value": "John Goerzen", "type": "finder"}, {"lang": "en", "value": "John Goerzen", "type": "remediation developer"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:github/OpenKermit/ckermit", "product": "C-Kermit", "vendor": "OpenKermit", "versions": [{"lessThan": "11.1.515", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "C-Kermit before 11.1.515 contains a heap buffer overflow vulnerability in putsrv() in ckcfns.c that allows malicious peers to write past the srvcmd buffer by sending crafted packets. Attackers can use Kermit repeat-count compression in server command, GET, or file-header packets to write attacker-chosen bytes beyond the heap buffer on servers or receiving instances."}], "id": "CVE-2026-129126", "lastModified": "2026-11-13T22:14:15.437", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.2, "baseSeverity": "CRITICAL", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "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:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-11-13T17:17:29.977", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcfns.c#L461"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/OpenKermit/ckermit/commit/37e54720779237897bc6887efac42fe138817897"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-heap-buffer-overflow-via-putsrv-packet-decoding"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

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