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OpenAdvisories
High ALAS2-2026-3254 1 CVE

Important: python-jwcrypto security update (Amazon Linux 2)

Published Apr 27, 2026 · Updated Apr 29, 2026

Summary

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-39373: 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.

Fixed packages 1

ReleasePackageFixed in
Amazon Linux · 2 python-jwcrypto 0:0.4.2-1.amzn2.0.3

Vulnerabilities 1

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-39373.html