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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-fjrm-76x2-c4q4 JWCrypto: JWE ZIP decompression bomb
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 08 Apr 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Latchset
Latchset jwcrypto
Vendors & Products Latchset
Latchset jwcrypto

Wed, 08 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

threat_severity

Important


Tue, 07 Apr 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 07 Apr 2026 20:45:00 +0000

Type Values Removed Values Added
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.
Title JWCrypto: JWE ZIP decompression bomb
Weaknesses CWE-409
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-07T20:22:57.790Z

Reserved: 2026-04-06T21:29:17.350Z

Link: CVE-2026-39373

cve-icon Vulnrichment

Updated: 2026-04-07T20:22:53.956Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-04-07T20:16:32.133

Modified: 2026-04-08T21:27:00.663

Link: CVE-2026-39373

cve-icon Redhat

Severity : Important

Publid Date: 2026-04-07T19:35:36Z

Links: CVE-2026-39373 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-08T19:46:13Z

Weaknesses