CVE-2026-53587

{"id": "CVE-2026-53587", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-53587", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-20T19:18:28.320266Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "libgit2", "product": "libgit2", "versions": [{"status": "affected", "version": "< 1.8.6"}, {"status": "affected", "version": ">= 1.9.0, < 1.9.5"}]}]}], "published": "2026-08-20T19:16:55.137", "references": [{"url": "https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/releases/tag/v1.8.6", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/releases/tag/v1.9.5", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-125"}, {"lang": "en", "value": "CWE-126"}, {"lang": "en", "value": "CWE-1284"}]}], "descriptions": [{"lang": "en", "value": "libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, libgit2 performs a fixed-size strncmp in set_data in src/libgit2/transports/smart_pkt.c without first verifying that the smart-protocol pkt-line capability buffer contains 14 bytes. A malicious Git server can make bytes after the pkt-line complete object-format=, causing format_str to advance beyond the pkt-line and the following memchr length calculation to underflow. The resulting heap out-of-bounds walk can crash a client during the first refs-advertisement packet over HTTP, HTTPS, SSH, or the Git protocol. This issue is fixed in versions 1.8.6 and 1.9.5."}, {"lang": "es", "value": "libgit2 es una implementaci\u00f3n port\u00e1til en C de los m\u00e9todos centrales de Git proporcionada como una biblioteca enlazable con una API s\u00f3lida, que permite integrar la funcionalidad de Git en su aplicaci\u00f3n. Antes de las versiones 1.8.6 y 1.9.5, libgit2 realiza un strncmp de tama\u00f1o fijo en set_data en src/libgit2/transports/smart_pkt.c sin verificar primero que el b\u00fafer de capacidad pkt-line del protocolo inteligente contenga 14 bytes. Un servidor Git malicioso puede hacer que los bytes despu\u00e9s de la pkt-line completen object-format=, haciendo que format_str avance m\u00e1s all\u00e1 de la pkt-line y que el c\u00e1lculo de longitud de memchr subsiguiente sufra un desbordamiento negativo. El recorrido resultante de la memoria din\u00e1mica (heap) fuera de l\u00edmites puede bloquear a un cliente durante el primer paquete de anuncio de referencias a trav\u00e9s de HTTP, HTTPS, SSH o el protocolo Git. Este problema est\u00e1 solucionado en las versiones 1.8.6 y 1.9.5."}], "lastModified": "2026-10-26T10:10:00.140", "sourceIdentifier": "security-advisories@github.com"}