Improper Handling of Highly Compressed Data (Data Amplification) Affecting keep package, versions <0.51.0-r4


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.29% (21st percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-KEEP-16133920
  • published23 Apr 2026
  • disclosed7 Apr 2026

Introduced: 7 Apr 2026

CVE-2026-39373  (opens in a new tab)
CWE-409  (opens in a new tab)

How to fix?

Upgrade Chainguard keep to version 0.51.0-r4 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream keep package and not the keep package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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 Base Scores

version 3.1