{"id":"CVE-2026-101918","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-101918","generatedAt":"2026-10-27T23:45:27.289Z","title":"This occurs when an attacker-controlled recursively nested payload reaches json.loads.","description":"PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get_signing_key_from_jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a result, documented PyJWT exception handling does not contain the failure. Consequently, an unauthenticated request can raise an exception that may produce an HTTP 500 response. The advisory-defined affected implementation also includes jwt/api_jwt.py, verify_signature=False. This issue is fixed in version 2.15.0.","published":"2026-09-28T21:17:13.000Z","lastModified":"2026-10-07T20:59:18.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-248"],"affected":["pyjwt project/pyjwt"],"epss":{"score":0.00413,"percentile":0.35321,"date":"2026-10-26","history":[{"date":"2026-09-29","score":0.00291,"percentile":0.19506}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-07T22:30:11.000Z","detail":{"from":"5.3","score":"7.5","severity":"HIGH","fromSeverity":"MEDIUM"},"summary":"Now scored CVSS 7.5 HIGH (was 5.3)."},{"kind":"new","label":"New CVE","at":"2026-09-28T21:17:13.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-09-28T21:17:13.410Z"},"summary":"New CVE, high severity (CVSS 7.5)."}],"references":[{"url":"https://github.com/jpadilla/pyjwt/commit/5fde08a6cf906aa7698de2d6391d88b73006b17b","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/releases/tag/2.15.0","tags":["Product","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-42vr-xj54-vc7v","tags":["Exploit","Mitigation","Vendor Advisory"],"source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-101918","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}