CVE-2026-53585: libgit2 · Unthrottled Resource Allocation
Affects libgit2Source GCVE Database
Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.9.5 or 1.8.6 when convenient.
Data as of 27 Oct 2026, 05:11 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.9.5, 1.8.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LExploitation evidence
Disclosed: evidence found.
CVE published 20 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade libgit2 to 1.9.5 or 1.8.6.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| libgit2 libgit2 | Affected
| Fixed in
|
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, git_delta_apply in src/libgit2/delta.c trusts the attacker-controlled res_sz value parsed by hdr_sz from a delta object header and passes that amount to git__malloc before validating delta instructions. Malicious pack data supplied through git_clone, git_fetch, git_remote_fetch, git_indexer_append, or a local attacker-supplied repository can use a very small multi-level OFS_DELTA chain to retain extremely large allocations and exhaust memory. This issue is fixed in versions 1.8.6 and 1.9.5.
References
- github.com/libgit2/libgit2/security/advisories/GHSA-27m5-gxxh-x79j (opens in a new tab)
- github.com/libgit2/libgit2/commit/0cdfdd5fa8f8514c82413025e1e0808866cf7c30 (opens in a new tab)
- github.com/libgit2/libgit2/commit/c1896f06df22cc0ca5658df3a8f6cd7ede4cd6ae (opens in a new tab)
- github.com/libgit2/libgit2/commit/dec22ac01ad9620c96b7b9ac3ef636ea46d43bed (opens in a new tab)
- github.com/libgit2/libgit2/releases/tag/v1.8.6 (opens in a new tab)
- github.com/libgit2/libgit2/releases/tag/v1.9.5 (opens in a new tab)