UBUNTU-CVE-2026-43632 (CVE-2026-43632)

Vulnerability from osv_ubuntu – Published: 2026-08-06 22:17 – Updated: 2026-08-13 00:06 – Source website
VLAI
Details

llama.cpp builds b7492 through the latest b9060 contains a use-after-free vulnerability in llama-server affecting six tokenization endpoints (/tokenize, /detokenize, /infill, /apply-template, /rerank, and /anthropic/count_tokens) that bypass the task queue and access ctx_server.vocab directly on HTTP worker threads. Attackers can exploit a time-of-check-time-of-use race condition where the main thread destroys and frees vocab after the synchronization lock is released but before the handler finishes using it, causing a crash or potential code execution when --sleep-idle-seconds is configured.

Severity
8.1 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
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
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libllama0",
            "binary_version": "8681+dfsg-1"
          },
          {
            "binary_name": "llama.cpp",
            "binary_version": "8681+dfsg-1"
          },
          {
            "binary_name": "llama.cpp-examples",
            "binary_version": "8681+dfsg-1"
          },
          {
            "binary_name": "llama.cpp-tests",
            "binary_version": "8681+dfsg-1"
          },
          {
            "binary_name": "llama.cpp-tools",
            "binary_version": "8681+dfsg-1"
          },
          {
            "binary_name": "llama.cpp-tools-extra",
            "binary_version": "8681+dfsg-1"
          },
          {
            "binary_name": "python3-gguf",
            "binary_version": "8681+dfsg-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "llama.cpp",
        "purl": "pkg:deb/ubuntu/llama.cpp@8681+dfsg-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5882+dfsg-2",
        "8064+dfsg-1ubuntu1",
        "8681+dfsg-1"
      ]
    }
  ],
  "aliases": [],
  "details": "llama.cpp builds b7492 through the latest b9060 contains a use-after-free vulnerability in llama-server affecting six tokenization endpoints (/tokenize, /detokenize, /infill, /apply-template, /rerank, and /anthropic/count_tokens) that bypass the task queue and access ctx_server.vocab directly on HTTP worker threads. Attackers can exploit a time-of-check-time-of-use race condition where the main thread destroys and frees vocab after the synchronization lock is released but before the handler finishes using it, causing a crash or potential code execution when --sleep-idle-seconds is configured.",
  "id": "UBUNTU-CVE-2026-43632",
  "modified": "2026-08-13T00:06:43Z",
  "published": "2026-08-06T22:17:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-43632"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-43632"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/Vladimir-tokarev-cyera/llama-cpp-security-patches"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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",
      "type": "CVSS_V4"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-43632"
  ]
}



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