Buffer overflow in Ggml-org Llama.cpp

CVE-2025-52566

llama.cpp is an inference of several LLM models in C/C++. Prior to version b5721, there is a signed vs. unsigned integer overflow in llama.cpp's tokenizer implementation (llama_vocab::tokenize) (src/llama-vocab.cpp:3036) resulting in unint…

Vulnerability class: Buffer Overflow

EPSS: 0.002 (45.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-52566?
CVE-2025-52566 is a high-severity vulnerability in Ggml-org Llama.cpp, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.6/10. Published 2025-06-24.
How severe is CVE-2025-52566?
High severity. CVSS v3 base score is 8.6 out of 10.
Is CVE-2025-52566 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.