Vulnerability · Published Oct 27, 2026 · Assigned by VulnCheck

CVE-2025-71439llama.cpp before b5649 Heap Out-of-Bounds Read via llama_vocab::impl::print_info

Medium 5.5

In plain English

A medium-severity out-of-bounds read in llama.cpp from ggml-org. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.5Medium

Exploit odds (30 days)0.1%top 98.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

llama.cpp before b5649 contains a heap out-of-bounds read vulnerability in llama_vocab::impl::print_info() that allows attackers to crash model loading via oversized special token IDs. Attackers can supply a crafted GGUF model with a short tokenizer.ggml.tokens array, causing llama-cli or llama-server to read past id_to_token and crash.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	llama.cpp	5713+dfsg-1	DEBIAN-CVE-2025-71439
Ubuntu:26.04:LTS	llama.cpp	no fix listed	UBUNTU-CVE-2025-71439
Ubuntu:26.10	llama.cpp	no fix listed	UBUNTU-CVE-2025-71439

Affected products (as reported)

Vendor	Product	Versions
ggml-org	llama.cpp	0 – before b5649

Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

GitHub Security Advisory (GHSA-g4cc-763q-h9h6) vendor-advisory
https://github.com/ggml-org/llama.cpp/pull/14145 patch, issue-tracking
https://github.com/ggml-org/llama.cpp/commit/c33fe8b8c4427202706b1434e9fc8ab5752c9cac patch
https://github.com/ggml-org/llama.cpp/blob/b5648/src/llama-vocab.cpp#L2771 technical-description
llama.cpp b5649 Release Notes release-notes
VulnCheck Advisory: llama.cpp before b5649 Heap Out-of-Bounds Read via llama_vocab::impl::print_info third-party-advisory