Out-of-bounds Read in Ggml-Org Llama.cpp
CVE-2025-71439
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.001 (1.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
Weakness classification (CWE)
References
- github.com/ggml-org/llama.cpp/blob/b5648/src/llama-vocab.cpp (technical-description)
- github.com/ggml-org/llama.cpp/commit/c33fe8b8c4427202706b1434e9fc8ab5752c9cac (patch)
- github.com/ggml-org/llama.cpp/pull/14145 (issue-tracking, patch)
- github.com/ggml-org/llama.cpp/releases/tag/b5649 (release-notes)
- github.com/ggml-org/llama.cpp/security/advisories/GHSA-g4cc-763q-h9h6 (vendor-advisory)
- www.vulncheck.com/advisories/llama-cpp-before-b5649-heap-out-of-bounds-read-via… (third-party-advisory)
Frequently asked questions
- What is CVE-2025-71439?
- CVE-2025-71439 is a medium-severity vulnerability in Ggml-Org Llama.cpp, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-10-27.
- How severe is CVE-2025-71439?
- Medium severity. CVSS v3 base score is 5.5 out of 10.