Integer overflow in Ggml-Org Llama.cpp
CVE-2026-116840
llama.cpp b5854 before b11275 contains an integer overflow vulnerability in gguf_init_from_reader that bypasses the CVE-2025-53630 size check when padding near-SIZE_MAX tensor sizes. Attackers can supply a crafted GGUF file whose tensor size pads to zero, causing an undersized data blob and out-of-bounds reads by consumers.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/ggml-org/llama.cpp/blob/v0.5.0/ggml/src/gguf.cpp (technical-description)
- github.com/ggml-org/llama.cpp/commit/a6ea155d3d38b3f6f43d0c0dc29c2d592413ef44 (patch)
- github.com/ggml-org/llama.cpp/issues/26978 (issue-tracking)
- github.com/ggml-org/llama.cpp/pull/26979 (issue-tracking, patch)
- github.com/ggml-org/llama.cpp/releases/tag/b11275 (release-notes)
- www.vulncheck.com/advisories/llama-cpp-b5854-before-b11275-integer-overflow-in-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-116840?
- CVE-2026-116840 is a medium-severity vulnerability in Ggml-Org Llama.cpp, classified under Integer Overflow or Wraparound. CVSS score: 6.1/10. Published 2026-10-27.
- How severe is CVE-2026-116840?
- Medium severity. CVSS v3 base score is 6.1 out of 10.