CVE-2026-53585 — libgit2: Unbounded Memory Allocation via Delta Object Result-Size Header
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 …
Published: 2026-08-20 · CVSS: 5.3 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7