{"cve":"CVE-2026-55244","nvd":{"published":"2026-09-14T20:16:47.640","modified":"2026-09-30T17:51:56.193","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H","score":5.0},"cwes":["CWE-248"],"references":["https://github.com/lmfit/asteval/commit/9c625b3674f8d05f206708bb85afca17a87694a4","https://github.com/lmfit/asteval/commit/c49c99a67acb63eb7410231932250bd820380e45","https://github.com/lmfit/asteval/pull/153","https://github.com/lmfit/asteval/releases/tag/1.0.9","https://github.com/lmfit/asteval/security/advisories/GHSA-89v8-rhwq-hf77"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-55244","score":0.00177,"percentile":0.07237,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-89v8-rhwq-hf77","url":"https://osv.dev/vulnerability/GHSA-89v8-rhwq-hf77","summary":"asteval has a Sandbox Escape via BaseException Subclasses","modified":"2026-09-10T12:25:42.196126429Z","packages":[{"ecosystem":"PyPI","name":"asteval","purl":"pkg:pypi/asteval","ranges":["<1.0.9"],"fixed":["1.0.9"]}]},{"id":"PYSEC-2026-3807","url":"https://osv.dev/vulnerability/PYSEC-2026-3807","summary":"asteval has a Sandbox Escape via BaseException Subclasses","modified":"2026-09-10T12:15:04.049966682Z","packages":[{"ecosystem":"PyPI","name":"asteval","purl":"pkg:pypi/asteval","ranges":["<1.0.9"],"fixed":["1.0.9"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}