CVE-2026-39853

{"id": "CVE-2026-39853", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-39853", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-04-09T16:13:50.325421Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.8}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "mtrojnar", "product": "osslsigncode", "versions": [{"status": "affected", "version": "< 2.12"}]}]}], "published": "2026-04-09T16:16:31.233", "references": [{"url": "https://github.com/mtrojnar/osslsigncode/commit/cbee1e723c5a8547302bd841ad9943ed8144db68", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/mtrojnar/osslsigncode/releases/tag/2.12", "tags": ["Product", "Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/mtrojnar/osslsigncode/security/advisories/GHSA-hx87-8754-xvh4", "tags": ["Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-121"}, {"lang": "en", "value": "CWE-787"}]}], "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."}, {"lang": "es", "value": "osslsigncode es una herramienta que implementa la firma y el sellado de tiempo Authenticode. Anterior a la 2.12, existe una vulnerabilidad de desbordamiento de b\u00fafer de pila en osslsigncode en varias rutas de verificaci\u00f3n de firma. Durante la verificaci\u00f3n de una firma PKCS#7, el c\u00f3digo copia el valor de resumen de una estructura SpcIndirectDataContent analizada en un b\u00fafer de pila de tama\u00f1o fijo (mdbuf[EVP_MAX_MD_SIZE], 64 bytes) sin validar que la longitud de origen encaje dentro del b\u00fafer de destino. Este patr\u00f3n est\u00e1 presente en los manejadores de verificaci\u00f3n para archivos PE, MSI, CAB y de script. Un atacante puede crear un archivo firmado malicioso con un campo de resumen sobredimensionado en SpcIndirectDataContent. Cuando un usuario verifica dicho archivo con osslsigncode verify, el memcpy sin l\u00edmites puede desbordar el b\u00fafer de pila y corromper el estado de pila adyacente. Esta vulnerabilidad est\u00e1 corregida en la 2.12."}], "lastModified": "2026-10-26T21:10:00.170", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:osslsigncode_project:osslsigncode:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "99F63D36-1A36-4A6E-A2A3-02B68D5BA069", "versionEndExcluding": "2.12"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}