CVE-2026-53583

{"id": "CVE-2026-53583", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-53583", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-20T19:03:44.491440Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.5, "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": "2026-08-20T19:16:54.500", "references": [{"url": "https://github.com/libgit2/libgit2/commit/647dcb432980b84ede4cb5a008bbd1ccb4ead03d", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/commit/c2aa35409ee0e6515df64da49750f13a0a42c47f", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/commit/ef086bc3e4eedf62be38a910381aae24d49871ff", "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-h7gc-w2gg-p9xp", "source": "security-advisories@github.com"}, {"url": "https://github.com/libgit2/libgit2/security/advisories/GHSA-h7gc-w2gg-p9xp", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-295"}, {"lang": "en", "value": "CWE-297"}]}], "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, verify_server_cert in src/libgit2/streams/openssl.c uses an inverted !!memcmp result in the GEN_IPADD branch when comparing an IP-literal host with a certificate IP SubjectAltName. OpenSSL builds reject matching IP addresses and accept mismatched IP addresses, allowing a network attacker with a CA-trusted certificate containing any IP SubjectAltName to intercept libgit2 connections to IP-literal HTTPS URLs. DNS SubjectAltName validation and non-OpenSSL TLS backends are not affected. This issue is fixed in versions 1.8.6 and 1.9.5."}], "lastModified": "2026-09-09T21:19:49.197", "sourceIdentifier": "security-advisories@github.com"}