{"id":"CVE-2026-53587","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-53587","generatedAt":"2026-10-28T04:33:44.623Z","title":"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.","description":"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.","published":"2026-08-20T19:16:55.000Z","lastModified":"2026-10-26T10:10:00.000Z","status":"Awaiting Analysis","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-20","CWE-125","CWE-126","CWE-1284"],"affected":[],"epss":{"score":0.0047,"percentile":0.40489,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"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"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-53587","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}