{"id":"CVE-2026-55830","summary":"RestrictedPython guard hooks can be shadowed via positional-only arguments","details":"RestrictedPython is a tool that helps to define a subset of the Python language which allows to provide a program input into a trusted environment. Prior to 8.3, check_function_argument_names() rejected protected guard hook names for regular, variadic, and keyword-only arguments but omitted positional-only arguments, allowing __getattr__, _getitem_, _write_, or _print_ to be shadowed by a local parameter and bypass the embedding application's access policy. This issue is fixed in version 8.3.","aliases":["GHSA-ffg3-p8fm-mjx2"],"modified":"2026-08-12T03:51:49.450427019Z","published":"2026-07-08T21:16:36.200Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-184"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55830.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55830.json"},{"type":"ADVISORY","url":"https://github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-ffg3-p8fm-mjx2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55830"},{"type":"FIX","url":"https://github.com/zopefoundation/RestrictedPython/commit/3737596ec9f28c34a073cc845bd2f4c0a80cb671"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/zopefoundation/restrictedpython","events":[{"introduced":"0"},{"fixed":"3737596ec9f28c34a073cc845bd2f4c0a80cb671"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"8.3"}]}}],"versions":["8.3a1.dev0","8.2","8.1","8.1a1.dev0","8.0","7.4","7.3","7.2","7.2a1.dev0","7.1","7.0","7.0a2.dev0","7.0a1.dev1","7.0a1.dev0","6.0","6.0a1.dev0","5.3a1.dev0","5.2","5.2a1.dev0","5.1","5.0","4.0","4.0b8","4.0b7","4.0b6","4.0b5","4.0b4","4.0b3","4.0b2","4.0b1","4.0a3","4.0a2","4.0a1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55830.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:L"}]}