{"cve":"CVE-2026-39373","nvd":{"published":"2026-04-07T20:16:32.133","modified":"2026-07-24T21:10:00.143","status":"Analyzed","description":"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.","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-409"],"references":["https://github.com/latchset/jwcrypto/security/advisories/GHSA-fjrm-76x2-c4q4"],"products":["latchset:jwcrypto"],"source":"nvd","synced_at":"2026-10-19T22:28:59.047572785+00:00"},"epss":{"cve":"CVE-2026-39373","score":0.00294,"percentile":0.22088,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-fjrm-76x2-c4q4","url":"https://osv.dev/vulnerability/GHSA-fjrm-76x2-c4q4","summary":"JWCrypto: JWE ZIP decompression bomb","modified":"2026-09-10T03:50:44.204901927Z","packages":[{"ecosystem":"PyPI","name":"jwcrypto","purl":"pkg:pypi/jwcrypto","ranges":["<1.5.7"],"fixed":["1.5.7"]}]},{"id":"PYSEC-2026-70","url":"https://osv.dev/vulnerability/PYSEC-2026-70","summary":"","modified":"2026-05-21T15:00:14.336277076Z","packages":[{"ecosystem":"PyPI","name":"jwcrypto","purl":"pkg:pypi/jwcrypto","ranges":["<1.5.7"],"fixed":["1.5.7"]}]}],"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."]}