Vulnerability · Published Aug 6, 2026 · Assigned by VulnCheck

CVE-2026-43628llama.cpp b3978–b9058 Integer Underflow via DRY Sampler

High 7.8

In plain English

A high-severity out-of-bounds read in llama.cpp from ggml-org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.2%top 85.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	llama.cpp	no fix listed	DEBIAN-CVE-2026-43628
Ubuntu:26.04:LTS	llama.cpp	no fix listed	UBUNTU-CVE-2026-43628
Ubuntu:26.10	llama.cpp	no fix listed	UBUNTU-CVE-2026-43628

Affected products (as reported)

Vendor	Product	Versions
ggml-org	llama.cpp	b3978 – through b9058

Weakness: CWE-191, CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

https://github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches mitigation
https://www.vulncheck.com/advisories/llama-cpp-b3978-b9058-integer-underflow-via-dry-sampler third-party-advisory