{"cve":"CVE-2026-48990","nvd":{"published":"2026-06-17T22:16:23.270","modified":"2026-10-26T12:10:00.130","status":"Deferred","description":"joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions 1.3.4 through 1.6.5, joserfc accepts oversized RFC7797 b64=false JWS payloads without applying JWSRegistry.max_payload_length, which can lead to resource exhaustion. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with ExceededSizeError. The RFC7797 unencoded payload paths do not make the same check. A valid b64=false compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than JWSRegistry.max_payload_length. Applications that accept lower-trust JWS values and rely on joserfc to reject oversized token content during verification have a moderate availability risk. This issue has been fixed in version 1.6.7.","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:L","score":5.3},"cwes":["CWE-400","CWE-770"],"references":["https://github.com/authlib/joserfc/releases/tag/1.6.7","https://github.com/authlib/joserfc/security/advisories/GHSA-wphv-vfrh-23q5","https://github.com/authlib/joserfc/security/advisories/GHSA-wphv-vfrh-23q5"],"products":[],"source":"nvd","synced_at":"2026-10-26T12:35:18.182177120+00:00"},"epss":{"cve":"CVE-2026-48990","score":0.00163,"percentile":0.05418,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-wphv-vfrh-23q5","url":"https://osv.dev/vulnerability/GHSA-wphv-vfrh-23q5","summary":"joserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization","modified":"2026-09-10T03:50:50.864205034Z","packages":[{"ecosystem":"PyPI","name":"joserfc","purl":"pkg:pypi/joserfc","ranges":[">=1.3.4 <1.6.7"],"fixed":["1.6.7"]}]},{"id":"PYSEC-2026-2530","url":"https://osv.dev/vulnerability/PYSEC-2026-2530","summary":"joserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization","modified":"2026-07-13T16:31:58.801108194Z","packages":[{"ecosystem":"PyPI","name":"joserfc","purl":"pkg:pypi/joserfc","ranges":[">=1.3.4 <1.6.7"],"fixed":["1.6.7"]}]}],"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."]}