{"id":"CVE-2026-102268","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-102268","generatedAt":"2026-10-28T05:28:10.425Z","title":"Consequently, an attacker who knows the public key can forge authenticated HMAC tokens.","description":"PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is_pem_format in jwt/utils.py is affected because is_pem_format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a mutated public-key PEM as raw key bytes. As a result, HMACAlgorithm.prepare_key treats the unrecognized asymmetric public key as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0.","published":"2026-09-28T21:17:15.000Z","lastModified":"2026-10-07T20:25:03.000Z","status":"Analyzed","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"cwe":["CWE-347"],"affected":["pyjwt project/pyjwt"],"epss":{"score":0.00236,"percentile":0.14495,"date":"2026-10-27","history":[{"date":"2026-09-29","score":0.00196,"percentile":0.08291}]},"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 (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-28T21:17:15.000Z","detail":{"score":"9.1","severity":"CRITICAL","publishedAt":"2026-09-28T21:17:14.600Z"},"summary":"New CVE, critical severity (CVSS 9.1)."}],"references":[{"url":"https://github.com/jpadilla/pyjwt/commit/8b4e233a22206b34ec1186e912e75c0b2396ac07","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/releases/tag/2.14.0","tags":["Product","Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9","tags":["Exploit","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9","tags":["Exploit","Vendor Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-102268","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."}