[ CVE-2026-119283 · Published 29 Oct 2026 ]
joserfc: Unbounded JWE General JSON `recipients` Array Leads to CPU Exhaustion (DoS) via Repeated RSA Private-Key Decryption
[ Why it matters ]Priority signals
- Public proof-of-concept exploit exists (CISA SSVC)
[ Description ]Official description
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.7.5, joserfc.jwe.decrypt_json() accepts a JWE General JSON Serialization recipients array without a count limit and calls decrypt_cek() for every entry. An unauthenticated attacker who can submit a JWE to an endpoint using an RSA key-management algorithm can choose the number of private-key decryption operations performed by one request. The verify_all_recipients option does not reduce this work because the affected loop processes every recipient before consulting that setting, allowing repeated requests to exhaust service CPU without affecting confidentiality or integrity. This issue is fixed in version 1.7.5.
[ Fixes ]Fixes and patches
- joserfc 1.7.5Fixed version · GitHub Advisories · pip package joserfc: upgrade to 1.7.5 or later (affected < 1.7.5)
[ Packages ]Affected open-source packages
- joserfc pipAffected < 1.7.5 · fixed in 1.7.5 · GHSA-jpxq-7h8p-2q76