CVE-2026-53585
libgit2: Unbounded Memory Allocation via Delta Object Result-Size Header
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.
INFO
Published Date :
Aug. 20, 2026, 7:16 p.m.
Last Modified :
Aug. 20, 2026, 7:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-53585
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update libgit2 to version 1.8.6 or later.
- Update libgit2 to version 1.9.5 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53585.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53585 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53585
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53585 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53585 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 20, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'libgit2', 'product': 'libgit2', 'versions': [{'status': 'affected', 'version': '< 1.8.6'}, {'status': 'affected', 'version': '>= 1.9.0, < 1.9.5'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-770 Added Reference https://github.com/libgit2/libgit2/commit/0cdfdd5fa8f8514c82413025e1e0808866cf7c30 Added Reference https://github.com/libgit2/libgit2/commit/c1896f06df22cc0ca5658df3a8f6cd7ede4cd6ae Added Reference https://github.com/libgit2/libgit2/commit/dec22ac01ad9620c96b7b9ac3ef636ea46d43bed Added Reference https://github.com/libgit2/libgit2/releases/tag/v1.8.6 Added Reference https://github.com/libgit2/libgit2/releases/tag/v1.9.5 Added Reference https://github.com/libgit2/libgit2/security/advisories/GHSA-27m5-gxxh-x79j