CVE-2026-39373
JWCrypto: JWE ZIP decompression bomb
- State
- Published
- Severity
- 5.3 Medium
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Reserved
- Apr 6, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | GitHub_M |
Weaknesses
- CWE-409 Improper Handling of Highly Compressed Data (Data Amplification)
Affected Products
| Product | Versions |
|---|---|
jwcryptolatchset |
|
References
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