CVE-2026-43631

llama.cpp builds b7492 through the latest b9060 contains a use-after-free vulnerability in the vocab pointer of llama-server when the --sleep-idle-seconds feature is enabled, allowing unauthenticated remote attackers to execute arbitrary code. Attackers can trigger the vulnerability by sending requests to affected endpoints while the server transitions to sleep mode, causing concurrent worker threads to dereference a freed vocab pointer that can be reclaimed with attacker-controlled data to achieve remote code execution.

CVSS 4.0

9.2CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

8.1CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 47% of CVEs (scores of 2026-10-25)

CWEs

CWE-362, CWE-416

Published

2026-08-06

Modified

2026-10-23

Record from

the NVD, synced 2026-10-24

Affected

• ggml:llama.cpp

References

• https://github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches
• https://www.vulncheck.com/advisories/llama-cpp-b7492-b9060-use-after-free-rce-via-llama-server

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