Improper Input Validation Affecting libgit2 package, versions <1.9.0+ds-2+deb13u1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN13-LIBGIT2-18470459
- published31 Jul 2026
- disclosed20 Aug 2026
Introduced: 31 Jul 2026
NewCVE-2026-53587 (opens in a new tab)How to fix?
Upgrade Debian:13 libgit2 to version 1.9.0+ds-2+deb13u1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream libgit2 package and not the libgit2 package as distributed by Debian.
See How to fix? for Debian:13 relevant fixed versions and status.
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.
References
- https://security-tracker.debian.org/tracker/CVE-2026-53587
- 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