CVE catalog
CVE-2026-53587
libgit2 vulnerabilities
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.47% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | libgit2 | sid | 1.9.7+ds-1 | fixed |
| Debian | libgit2 | forky | 1.9.7+ds-1 | fixed |
| Debian | libgit2 | trixie | 1.9.0+ds-2+deb13u1 | fixed |
| Debian | libgit2 | trixie-security | 1.9.0+ds-2+deb13u1 | fixed |
| Debian | libgit2 | bookworm | 1.5.1+ds-1+deb12u1 | not affected |
| Debian | libgit2 | bookworm-security | 1.5.1+ds-1+deb12u2 | not affected |
| Ubuntu | libgit2 | noble | 1.7.2+ds-1ubuntu3.1 | fixed |
| Ubuntu | libgit2-1.7 | noble | 1.7.2+ds-1ubuntu3.1 | fixed |
| Ubuntu | libgit2-dev | noble | 1.7.2+ds-1ubuntu3.1 | fixed |
| Ubuntu | libgit2-fixtures | noble | 1.7.2+ds-1ubuntu3.1 | fixed |
| Ubuntu | libgit2 | 24.04 | 1.5.1+ds-1ubuntu1 | vulnerable |
| Ubuntu | libgit2 | 24.04 | 1.7.1+ds-2ubuntu1 | vulnerable |
| Ubuntu | libgit2 | 24.04 | 1.7.2+ds-1ubuntu1 | vulnerable |
| Ubuntu | libgit2 | 24.04 | 1.7.2+ds-1ubuntu2 | vulnerable |
| Ubuntu | libgit2 | 24.04 | 1.7.2+ds-1ubuntu3 | vulnerable |
| Ubuntu | libgit2 | 24.04 | 1.7.2+ds-1ubuntu3.1 | fixed |
| Ubuntu | libgit2 | 26.04 | 1.9.0+ds-2ubuntu2 | vulnerable |
| Ubuntu | libgit2 | 26.04 | 1.9.1+ds-1ubuntu1 | vulnerable |
| Ubuntu | libgit2 | 26.04 | 1.9.1+ds-1ubuntu1.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | libgit2 | source | sid | 1.9.6+ds-1 | not yet assigned | Not reported | Not reported |
| Debian | libgit2 | source | forky | 1.9.6+ds-1 | not yet assigned | Not reported | Not reported |
| Debian | libgit2 | source | trixie | 1.9.0+ds-2+deb13u1 | not yet assigned | Not reported | Not reported |
| Debian | libgit2 | source | bookworm | Not affected | unimportant | Not reported | Not reported |
| Ubuntu | libgit2 | deb | noble | 1.7.2+ds-1ubuntu3.1 | Not reported | Not reported | Not reported |
| Ubuntu | libgit2-1.7 | deb | noble | 1.7.2+ds-1ubuntu3.1 | Not reported | Not reported | Not reported |
| Ubuntu | libgit2-dev | deb | noble | 1.7.2+ds-1ubuntu3.1 | Not reported | Not reported | Not reported |
| Ubuntu | libgit2-fixtures | deb | noble | 1.7.2+ds-1ubuntu3.1 | Not reported | Not reported | Not reported |
| Ubuntu | libgit2 | deb | 24.04 | 1.7.2+ds-1ubuntu3.1 | Not reported | UBUNTU-CVE-2026-53587 | Not reported |
| Ubuntu | libgit2 | deb | 26.04 | 1.9.1+ds-1ubuntu1.1 | Not reported | UBUNTU-CVE-2026-53587 | Not reported |
OpenFactory catalog packages
[Debian 13 (Trixie)]
- [libgit2-1.9]Affected
Source package: [libgit2]
Details (4)
1.9.0+ds-2· amd64 · trixieAffected · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2· arm64 · trixieAffected · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2+deb13u1· arm64 · trixie-securityFixed · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
- [libgit2-dev]Affected
Source package: [libgit2]
Details (4)
1.9.0+ds-2· amd64 · trixieAffected · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2· arm64 · trixieAffected · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2+deb13u1· amd64 · trixie-securityFixed · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2+deb13u1· arm64 · trixie-securityFixed · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
- [libgit2-fixtures]Affected
Source package: [libgit2]
Details (4)
1.9.0+ds-2· all · trixieAffected · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2· all · trixieAffected · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2+deb13u1· all · trixie-securityFixed · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
1.9.0+ds-2+deb13u1· all · trixie-securityFixed · Fixed:
1.9.0+ds-2+deb13u1usn · libgit2 · debian · 13
[Debian 12 (Bookworm)]
- [libgit2-1.5]Not affected
Source package: [libgit2]
Details (4)
1.5.1+ds-1+deb12u1· amd64 · bookwormNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· arm64 · bookwormNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· amd64 · bookworm-securityNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· arm64 · bookworm-securityNot affected
usn · libgit2 · debian · bookworm
- [libgit2-1.8]Not affected
Source package: [libgit2]
Details (2)
1.8.4+ds-3~bpo12+1· amd64 · bookworm-backportsNot affected
usn · libgit2 · debian · bookworm
1.8.4+ds-3~bpo12+1· arm64 · bookworm-backportsNot affected
usn · libgit2 · debian · bookworm
- [libgit2-dev]Not affected
Source package: [libgit2]
Details (6)
1.5.1+ds-1+deb12u1· amd64 · bookwormNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· arm64 · bookwormNot affected
usn · libgit2 · debian · bookworm
1.8.4+ds-3~bpo12+1· amd64 · bookworm-backportsNot affected
usn · libgit2 · debian · bookworm
1.8.4+ds-3~bpo12+1· arm64 · bookworm-backportsNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· amd64 · bookworm-securityNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· arm64 · bookworm-securityNot affected
usn · libgit2 · debian · bookworm
- [libgit2-fixtures]Not affected
Source package: [libgit2]
Details (6)
1.5.1+ds-1+deb12u1· all · bookwormNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· all · bookwormNot affected
usn · libgit2 · debian · bookworm
1.8.4+ds-3~bpo12+1· all · bookworm-backportsNot affected
usn · libgit2 · debian · bookworm
1.8.4+ds-3~bpo12+1· all · bookworm-backportsNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· all · bookworm-securityNot affected
usn · libgit2 · debian · bookworm
1.5.1+ds-1+deb12u1· all · bookworm-securityNot affected
usn · libgit2 · debian · bookworm
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11315-1.json]
- [https://github.com/libgit2/libgit2/commit/2c0ce8c0132ac38ab0db28239462a671e2e5440e]
- [https://github.com/libgit2/libgit2/commit/affda60c10fcef16723451c0d7dc71b71dc20ad3]
- [https://github.com/libgit2/libgit2/commit/d7a9fb87f504434e9f45228678953c4fa56e7640]
- [https://github.com/libgit2/libgit2/releases/tag/v1.8.6]
- [https://github.com/libgit2/libgit2/releases/tag/v1.9.5]
- [https://github.com/libgit2/libgit2/security/advisories/GHSA-pm24-4jhq-3xvm]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-53587]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-53587]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-53587]
- [https://security-tracker.debian.org/tracker/CVE-2026-53587]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53587.json]
- [https://ubuntu.com/security/notices/USN-8628-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-3333.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]