Out-of-bounds Read in Ggml Llama.cpp

CVE-2026-43628

llama.cpp builds b3978 through b9058 contain an integer underflow and out-of-bounds read vulnerability in the DRY sampler that allows unauthenticated attackers to trigger a heap buffer underflow by sending a crafted HTTP request with dry_allowed_length set to INT32_MIN to the /v1/completions or /v1/chat/completions endpoints. Attackers can exploit this vulnerability to crash the server with SIGSEGV causing denial of service for all connected users, or corrupt token sampling probabilities by reading garbage values from memory before the allocated buffer.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (10.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-43628?
CVE-2026-43628 is a high-severity vulnerability in Ggml Llama.cpp, classified under Out-of-bounds Read. CVSS score: 7.8/10. Published 2026-08-06.
How severe is CVE-2026-43628?
High severity. CVSS v3 base score is 7.8 out of 10.