CVE-2026-43631 Details
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.
A use-after-free vulnerability has been identified in llama.cpp versions b7492 through b9060. The issue arises in the vocab pointer of llama-server when the --sleep-idle-seconds feature is enabled. This vulnerability allows unauthenticated remote attackers to execute arbitrary code. Exploitation involves sending requests to affected endpoints while the server is transitioning to sleep mode, causing concurrent worker threads to dereference a freed vocab pointer. This pointer can then be reclaimed with attacker-controlled data, leading to remote code execution.
Users can apply the patch available in the llama.cpp security patches repository to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Aug 7, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches | [email protected] | PatchThird Party Advisory |
| https://www.vulncheck.com/advisories/llama-cpp-b7492-b9060-use-after-free-rce-via-llama-server | [email protected] | PatchThird Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') | CISA-ADP |
| CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') | [email protected] |
| CWE-416 | Use After Free | CISA-ADP |
| CWE-416 | Use After Free | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| ggml llama.cpp | >= b7492, <= b9060 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 21, 2026 | Initial Analysis | [email protected] |
| Aug 7, 2026 | CVE Modified | [email protected] |
| Aug 7, 2026 | CVE Modified | CISA-ADP |
| Aug 6, 2026 | New CVE Received | [email protected] |