CVE-2026-43631
llama.cpp b7492–b9060 Use-After-Free RCE via llama-server
CVE-2026-43631 is a critical vulnerability (CVSS 9.2) in Ggml Llama.cpp, published August 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.57%, the 47th percentile. No source names a fixed version.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.2
llama.cpp b7492–b9060 Use-After-Free RCE via llama-server
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.
- Record
CVE-2026-43631- CVSS 4.0
- 9.2 Critical
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 - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416, CWE-362, CWE-416, CWE-362
- Updated
- 2026-11-02
EUVDEUVD-2026-54286
9.2
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.
- Record
EUVD-2026-54286- CVSS 4.0
- 9.2 Critical
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6hc7-9rph-cm99
9.2
llama.cpp builds b7492 through the latest b9060 contains a use-after-free vulnerability in the...
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.
- Record
GHSA-6hc7-9rph-cm99- CVSS 4.0
- 9.2 Critical
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 - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-362
- Updated
- 2026-11-02
NVD
9.2
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.
- Record
CVE-2026-43631- CVSS 4.0
- 9.2 Critical
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 - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-362, CWE-416
- Updated
- 2026-11-02
OSV
9.2
llama.cpp b7492–b9060 Use-After-Free RCE via llama-server
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.
- Record
CVE-2026-43631- CVSS 4.0
- 9.2 Critical
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 - Weakness
- CWE-362, CWE-416
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-43631
9.2
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.
- Record
DEBIAN-CVE-2026-43631- CVSS 4.0
- 9.2 Critical
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 - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-43631
9.2
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.
- Record
UBUNTU-CVE-2026-43631- CVSS 4.0
- 9.2 Critical
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 - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
llama.cppDebian:14 |
All versions, plus listed versions 10108+dfsg-110108+dfsg1-110108+dfsg1-210192+dfsg-110192+dfsg-2 Show 45 moreShow less10192+dfsg-2~exp110271+dfsg-110344+dfsg-110438+dfsg-11:0.1.2+dfsg-1~exp11:0.2.0+dfsg1-11:0.2.0+dfsg1-1~exp11:0.4.0+dfsg-11:0.4.1+dfsg-11:0.5.0+dfsg-11:0.5.0+dfsg-21:0.6.0+dfsg-11:0.6.0+dfsg-21:0.7.0+dfsg-11:0.7.0+dfsg-25151+dfsg-1~exp25151+dfsg-1~exp35318+dfsg-15318+dfsg-25713+dfsg-15760+dfsg-15760+dfsg-25760+dfsg-35760+dfsg-45882+dfsg-15882+dfsg-25882+dfsg-35882+dfsg-3~exp15882+dfsg-3~exp25882+dfsg-3~exp35882+dfsg-46641+dfsg-16641+dfsg-26641+dfsg-37593+dfsg-17593+dfsg-27593+dfsg-37965+dfsg-18064+dfsg-18064+dfsg-28461+dfsg-18611+dfsg-18681+dfsg-18870+dfsg-18941+dfsg-1 |
None known |
llama.cppUbuntu:26.10 |
All versions, plus listed versions 8681+dfsg-19721+dfsg-1ubuntu110438+dfsg-110438+dfsg-1ubuntu1 |
None known |
llama.cppUbuntu:26.04:LTS |
All versions, plus listed versions 5882+dfsg-28064+dfsg-1ubuntu18681+dfsg-1 |
None known |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-02 | created | CVE List, EUVD, GitHub Advisories, NVD, OSV |
References
github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches
vulncheck.com/advisories/llama-cpp-b7492-b9060-use-after-free-rce-via-llama-server
nvd.nist.gov/vuln/detail/CVE-2026-43631
github.com/advisories/GHSA-6hc7-9rph-cm99
github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43631.json
security-tracker.debian.org/tracker/CVE-2026-43631
ubuntu.com/security/CVE-2026-43631
cve.org/CVERecord?id=CVE-2026-43631
Left out here: 13 versions. The JSON record has them.