{"id":"PYSEC-2026-70","details":"JWCrypto implements JWK, JWS, and JWE specifications using python-cryptography. Prior to 1.5.7, an unauthenticated attacker can exhaust server memory by sending crafted JWE tokens with ZIP compression. The existing patch for CVE-2024-28102  limits input token size to 250KB but does not validate the decompressed output size. An unauthenticated attacker can cause memory exhaustion on memory-constrained systems. A token under the 250KB input limit can decompress to approximately 100MB. This vulnerability is fixed in 1.5.7.","aliases":["CVE-2026-39373","GHSA-fjrm-76x2-c4q4"],"modified":"2026-05-21T15:00:14.336277076Z","published":"2026-04-07T20:16:32.133Z","references":[{"type":"EVIDENCE","url":"https://github.com/latchset/jwcrypto/security/advisories/GHSA-fjrm-76x2-c4q4"}],"affected":[{"package":{"name":"jwcrypto","ecosystem":"PyPI","purl":"pkg:pypi/jwcrypto"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.7"}]}],"versions":["0.2.0","0.2.1","0.3.0","0.3.1","0.4.0","0.4.1","0.4.2","0.5.0","0.6.0","0.7","0.8","0.9","0.9.1","1.0","1.2","1.3","1.3.1","1.4","1.4.1","1.4.2","1.5.0","1.5.1","1.5.2","1.5.3","1.5.4","1.5.5","1.5.6"],"ecosystem_specific":{},"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/jwcrypto/PYSEC-2026-70.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}