CVE-2026-39373

A flaw was found in JWCrypto, a Python library for JSON Web Key (JWK), JSON Web Signature (JWS), and JSON Web Encryption (JWE) specifications. An unauthenticated attacker can exploit this vulnerability by sending specially crafted JWE tokens that use ZIP compression. While the input token size is limited, the decompressed output size is not validated, allowing an attacker to cause excessive memory consumption. This can lead to memory exhaustion on affected systems, resulting in a Denial of Service (DoS).

This is an Important denial of service vulnerability in JWCrypto, a Python library used in Red Hat products such as Red Hat Ansible Automation Platform and Red Hat Enterprise Linux. An unauthenticated attacker can send specially crafted JWE tokens with ZIP compression, leading to excessive memory consumption and potential system exhaustion. This can result in a denial of service on affected systems.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.