{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-39853", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-04-07T19:13:20.378Z", "datePublished": "2026-04-09T15:50:26.548Z", "dateUpdated": "2026-04-09T16:15:19.583Z"}, "containers": {"cna": {"title": "osslsigncode has a Stack Buffer Overflow via Unbounded Digest Copy During Signature Verification", "problemTypes": [{"descriptions": [{"cweId": "CWE-121", "lang": "en", "description": "CWE-121: Stack-based Buffer Overflow", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-787", "lang": "en", "description": "CWE-787: Out-of-bounds Write", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-hx87-8754-xvh4", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-hx87-8754-xvh4"}, {"name": "https://github.com/mtrojnar/osslsigncode/commit/cbee1e723c5a8547302bd841ad9943ed8144db68", "tags": ["x_refsource_MISC"], "url": "https://github.com/mtrojnar/osslsigncode/commit/cbee1e723c5a8547302bd841ad9943ed8144db68"}, {"name": "https://github.com/mtrojnar/osslsigncode/releases/tag/2.12", "tags": ["x_refsource_MISC"], "url": "https://github.com/mtrojnar/osslsigncode/releases/tag/2.12"}], "affected": [{"vendor": "mtrojnar", "product": "osslsigncode", "versions": [{"version": "< 2.12", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-04-09T15:50:26.548Z"}, "descriptions": [{"lang": "en", "value": "osslsigncode is a tool that implements Authenticode signing and timestamping. Prior to 2.12, A stack buffer overflow vulnerability exists in osslsigncode in several signature verification paths. During verification of a PKCS#7 signature, the code copies the digest value from a parsed SpcIndirectDataContent structure into a fixed-size stack buffer (mdbuf[EVP_MAX_MD_SIZE], 64 bytes) without validating that the source length fits within the destination buffer. This pattern is present in the verification handlers for PE, MSI, CAB, and script files. An attacker can craft a malicious signed file with an oversized digest field in SpcIndirectDataContent. When a user verifies such a file with osslsigncode verify, the unbounded memcpy can overflow the stack buffer and corrupt adjacent stack state. This vulnerability is fixed in 2.12."}], "source": {"advisory": "GHSA-hx87-8754-xvh4", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-04-09T16:13:50.325421Z", "id": "CVE-2026-39853", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-04-09T16:15:19.583Z"}}]}}

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