{"cve":"CVE-2024-53861","nvd":{"published":"2024-11-29T19:15:09.433","modified":"2026-06-17T08:09:25.893","status":"Analyzed","description":"pyjwt is a JSON Web Token implementation in Python. An incorrect string comparison is run for `iss` checking, resulting in `\"acb\"` being accepted for `\"_abc_\"`. This is a bug introduced in version 2.10.0: checking the \"iss\" claim changed from `isinstance(issuer, list)` to `isinstance(issuer, Sequence)`. Since str is a Sequnce, but not a list, `in` is also used for string comparison. This results in `if \"abc\" not in \"__abcd__\":` being checked instead of `if \"abc\" != \"__abc__\":`. Signature checks are still present so real world impact is likely limited to denial of service scenarios. This issue has been patched in version 2.10.1. All users are advised to upgrade. There are no known workarounds for this vulnerability.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-697"],"references":["https://github.com/jpadilla/pyjwt/commit/1570e708672aa9036bc772476beae8bfa48f4131#diff-6893ad4a1c5a36b8af3028db8c8bc3b62418149843fc382faf901eaab008e380R366","https://github.com/jpadilla/pyjwt/commit/33022c25525c1020869c71ce2a4109e44ae4ced1","https://github.com/jpadilla/pyjwt/security/advisories/GHSA-75c5-xw7c-p5pm"],"products":["pyjwt_project:pyjwt"],"source":"nvd","synced_at":"2026-10-19T21:57:34.731061660+00:00"},"epss":{"cve":"CVE-2024-53861","score":0.00832,"percentile":0.57623,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-75c5-xw7c-p5pm","url":"https://osv.dev/vulnerability/GHSA-75c5-xw7c-p5pm","summary":"PyJWT Issuer field partial matches allowed","modified":"2026-09-10T03:50:21.333090692Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":[">=2.10.0 <2.10.1"],"fixed":["2.10.1"]}]},{"id":"PYSEC-2026-1814","url":"https://osv.dev/vulnerability/PYSEC-2026-1814","summary":"PyJWT Issuer field partial matches allowed","modified":"2026-07-07T17:48:03.529862550Z","packages":[{"ecosystem":"PyPI","name":"pyjwt","purl":"pkg:pypi/pyjwt","ranges":[">=2.10.0 <2.10.1"],"fixed":["2.10.1"]}]}],"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."]}