CVE-2026-43631

llama.cpp b7492–b9060 Use-After-Free RCE via llama-server

At a glance

Severity: CRITICAL 9.2
EPSS: EPSS 0.57 % · percentile 47 (2026-10-27)
State: PUBLISHED
Published: 2026-08-06
Updated: 2026-08-14
Assigner: VulnCheck
NVD status: Analyzed

Description

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.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	CRITICAL 9.2	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N	VulnCheck
CVSS 3.1	HIGH 8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	VulnCheck
CVSS 4.0	CRITICAL 9.2	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · disclosure@vulncheck.com (Secondary)
CVSS 3.1	HIGH 8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H	NVD · disclosure@vulncheck.com (Secondary)

Weaknesses (CWE)

European references

ENISA EUVD · EUVD-2026-54286
GCVE · GCVE-0-2026-43631

Affected configurations (NVD CPE)

cpe:2.3:a:ggml:llama.cpp:*:*:*:*:*:*:*:* ≥ b7492 ≤ b9060

Affected products

Product	Versions
ggml-org · llama.cpp	affected b7492 ≤ b9060

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD