---
id: CVE-2026-53585
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, git_delta_apply in
  src/libgit2/delta.c t…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-770
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-2026-53585'
references:
  - url: >-
      https://github.com/libgit2/libgit2/commit/0cdfdd5fa8f8514c82413025e1e0808866cf7c30
    label: security-advisories@github.com
  - url: >-
      https://github.com/libgit2/libgit2/commit/c1896f06df22cc0ca5658df3a8f6cd7ede4cd6ae
    label: security-advisories@github.com
  - url: >-
      https://github.com/libgit2/libgit2/commit/dec22ac01ad9620c96b7b9ac3ef636ea46d43bed
    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-27m5-gxxh-x79j'
    label: security-advisories@github.com
  - url: 'https://github.com/libgit2/libgit2/security/advisories/GHSA-27m5-gxxh-x79j'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00329
epssPercentile: 0.26284
ingestedAt: '2026-09-09T21:22:45.545Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.