{"id":"CVE-2026-53587","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","summary":"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…","severity":"high","cvss":7.5,"cvssVector":"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"],"vendor":"libgit2","product":"libgit2","affected":["libgit2 < 1.8.6","libgit2 >= 1.9.0, < 1.9.5"],"published":"2026-08-20","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:19:49.197","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53587","references":[{"url":"https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e","label":"security-advisories@github.com"},{"url":"https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3","label":"security-advisories@github.com"},{"url":"https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640","label":"security-advisories@github.com"},{"url":"https://github.com/libgit2/libgit2/releases/tag/v1.8.6","label":"security-advisories@github.com"},{"url":"https://github.com/libgit2/libgit2/releases/tag/v1.9.5","label":"security-advisories@github.com"},{"url":"https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm","label":"security-advisories@github.com"},{"url":"https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53587.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-53587"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2520693"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-53587"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53587"},{"url":"https://access.redhat.com/errata/RHSA-2026:67286"},{"url":"https://access.redhat.com/errata/RHSA-2026:67285"},{"url":"https://access.redhat.com/errata/RHSA-2026:59361"},{"url":"https://access.redhat.com/errata/RHSA-2026:69096"},{"url":"https://access.redhat.com/errata/RHSA-2026:69097"},{"url":"https://access.redhat.com/errata/RHSA-2026:69109"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"yes","technicalImpact":"partial","timestamp":"2026-08-20T19:18:28.320266Z"},"ingestedAt":"2026-09-14T08:50:24.132Z","epss":0.0047,"epssPercentile":0.39728,"exploits":{"github":1,"githubRepos":["https://github.com/Alixploit22/CVE-2026-53587"],"checkedAt":"2026-09-21T15:29:27.517Z"},"patched":["enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_codeready_linux_builder_v_10","hardened_images"],"slug":"CVE-2026-53587","body":"## Overview\n\nlibgit2 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:67286** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67286)\n- **RHSA-2026:67285** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67285)\n- **RHSA-2026:59361** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59361)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux AI (RHEL AI) 3 · no fix planned: Red Hat Enterprise Linux 8, Red Hat Enterprise Linux AI (RHEL AI) 3 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53587.json)\n- **RHSA-2026:69096** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69096)\n- **RHSA-2026:69097** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69097)\n- **RHSA-2026:69109** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69109)","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[]}