[ CVE-2026-88351 · Published 24 Sep 2026 ]
Vulnerability
CVSS 9.8
EPSS <1%No fix listed yet
[ Why it matters ]Priority signals
- Public proof-of-concept exploit exists (CISA SSVC)
- Critical severity: CVSS 9.8
[ Description ]Official description
An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.