CVE-2026-39373: CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) in latchset jwcrypto
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.
AI Analysis
Technical Summary
The vulnerability in jwcrypto before version 1.5.7 involves improper handling of highly compressed data (CWE-409). Specifically, while input JWE tokens are limited to 250KB, the decompressed data size is not validated, allowing an attacker to send a compressed token that decompresses to about 100MB. This can exhaust server memory and cause denial of service. The vulnerability is fixed in version 1.5.7.
Potential Impact
An unauthenticated attacker can cause denial of service by exhausting server memory through sending specially crafted JWE tokens with ZIP compression. This impacts availability on memory-constrained systems but does not affect confidentiality or integrity.
Mitigation Recommendations
Upgrade jwcrypto to version 1.5.7 or later, where this vulnerability is fixed by validating decompressed output size. Patch status is confirmed fixed in 1.5.7. No other mitigations are indicated.
CVE-2026-39373: CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) in latchset jwcrypto
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.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in jwcrypto before version 1.5.7 involves improper handling of highly compressed data (CWE-409). Specifically, while input JWE tokens are limited to 250KB, the decompressed data size is not validated, allowing an attacker to send a compressed token that decompresses to about 100MB. This can exhaust server memory and cause denial of service. The vulnerability is fixed in version 1.5.7.
Potential Impact
An unauthenticated attacker can cause denial of service by exhausting server memory through sending specially crafted JWE tokens with ZIP compression. This impacts availability on memory-constrained systems but does not affect confidentiality or integrity.
Mitigation Recommendations
Upgrade jwcrypto to version 1.5.7 or later, where this vulnerability is fixed by validating decompressed output size. Patch status is confirmed fixed in 1.5.7. No other mitigations are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-06T21:29:17.350Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d56287aaed68159a58f97b
Added to database: 4/7/2026, 8:01:11 PM
Last enriched: 4/7/2026, 8:17:28 PM
Last updated: 4/8/2026, 2:00:09 AM
Views: 4
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