{"cve":"CVE-2017-11424","nvd":{"published":"2017-08-24T16:29:00.197","modified":"2026-06-17T01:01:47.717","status":"Modified","description":"In PyJWT 1.5.0 and below the `invalid_strings` check in `HMACAlgorithm.prepare_key` does not account for all PEM encoded public keys. Specifically, the PKCS1 PEM encoded format would be allowed because it is prefaced with the string `-----BEGIN RSA PUBLIC KEY-----` which is not accounted for. This enables symmetric/asymmetric key confusion attacks against users using the PKCS1 PEM encoded public keys, which would allow an attacker to craft JWTs from scratch.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":[],"references":["http://www.debian.org/security/2017/dsa-3979","https://github.com/jpadilla/pyjwt/pull/277","http://www.debian.org/security/2017/dsa-3979","https://github.com/jpadilla/pyjwt/pull/277"],"products":["debian:debian_linux","pyjwt_project:pyjwt"],"source":"nvd","synced_at":"2026-10-19T20:44:47.710380879+00:00"},"epss":{"cve":"CVE-2017-11424","score":0.01804,"percentile":0.7855,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-r9jw-mwhq-wp62","url":"https://osv.dev/vulnerability/GHSA-r9jw-mwhq-wp62","summary":"PyJWT vulnerable to key confusion attacks","modified":"2024-12-05T05:30:36.784778Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":["<1.5.1"],"fixed":["1.5.1"]}]},{"id":"PYSEC-2017-24","url":"https://osv.dev/vulnerability/PYSEC-2017-24","summary":"","modified":"2023-11-08T03:58:49.234860Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":["<1.5.1"],"fixed":["1.5.1"]}]}],"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."]}