{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.0.9"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9c625b3674f8d05f206708bb85afca17a87694a4"
            },
            {
              "fixed": "c49c99a67acb63eb7410231932250bd820380e45"
            },
            {
              "fixed": "0b359d0b03195d1288af656e98730ab691b04f5a"
            }
          ],
          "repo": "https://github.com/lmfit/asteval",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-89v8-rhwq-hf77"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-248"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55244.json"
  },
  "details": "ASTEVAL is an evaluator of Python expressions and statements. Prior to 1.0.9, FROM_PY in asteval/astutils.py exposes BaseException, SystemExit, KeyboardInterrupt, and GeneratorExit to expressions evaluated by asteval.Interpreter.eval(), while run() and eval() in asteval/asteval.py catch Exception rather than these non-Exception BaseException subclasses. When an attacker-controlled expression raises one of these classes, on_raise() passes the class to raise_exception(), and the resulting exception bypasses the interpreter's safety handlers and propagates into the calling application. A consuming service that evaluates untrusted expressions can therefore be terminated or have signal and cleanup handling disrupted, causing denial of service. The separately documented read-only open() capability is not part of this vulnerability. This issue is fixed in version 1.0.9.",
  "id": "CVE-2026-55244",
  "modified": "2026-09-18T03:30:38.699219336Z",
  "published": "2026-09-14T20:00:24.584Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lmfit/asteval/releases/tag/1.0.9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55244.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/lmfit/asteval/security/advisories/GHSA-89v8-rhwq-hf77"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55244"
    },
    {
      "type": "FIX",
      "url": "https://github.com/lmfit/asteval/commit/9c625b3674f8d05f206708bb85afca17a87694a4"
    },
    {
      "type": "FIX",
      "url": "https://github.com/lmfit/asteval/commit/c49c99a67acb63eb7410231932250bd820380e45"
    },
    {
      "type": "FIX",
      "url": "https://github.com/lmfit/asteval/pull/153"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ASTEVAL: Sandbox Escape via BaseException Subclasses"
}