CVE-2026-27940CWE-122CWE-190

llama.cpp has a Heap Buffer Overflow via Integer Overflow in `mem_size` Calculation — Bypass of CVE-2025-53630 Fix

High · published March 12, 2026

CVSS v3.1
7.8
EPSS
0%
Percentile
8.0
In the wild
Unconfirmed
What it is

llama.cpp is an inference of several LLM models in C/C++. Prior to b8146, the gguf_init_from_file_impl() in gguf.cpp is vulnerable to an Integer overflow, leading to an undersized heap allocation. Using the subsequent fread() writes 528+ bytes of attacker-controlled data past the buffer boundary. This is a bypass of a similar bug in the same file - CVE-2025-53630, but the fix overlooked some areas. This vulnerability is fixed in b8146.

The record
Technical detail
CVSS v3.1
7.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00188 · 8.0th percentile
Weaknesses
CWE-122 · Heap-based Buffer Overflow; CWE-190 · Integer Overflow or Wraparound
Published
2026-03-12T16:39Z
EPSS history
Timeline
  • 12 MAR 16:39Z
    llama.cpp has a Heap Buffer Overflow via Integer Overflow in `mem_size` Calculation — Bypass of CVE-2025-53630 Fix
    cvelistv5