Bug 2567024

Summary: CVE-2026-119284 python-joserfc: joserfc: Denial of Service via excessive memory allocation during JWS deserialization [fedora-44]
Product: [Fedora] Fedora Reporter: Oleg Sushchenko <osushche>
Component: python-joserfcAssignee: Chih-Tao Lee <chihlee>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: 44CC: chihlee
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["0edd01da-8f57-4d98-b130-fe9961218684"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On:    
Bug Blocks: 2563708    

Description Oleg Sushchenko 2026-11-04 15:31:52 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to 1.7.6, joserfc compact JWS deserialization calls bytes.split() before enforcing the existing aggregate segment-size limits. When attacker-controlled compact serialization bytes reach deserialize_compact(), the split creates copies of the header, payload, and signature segments before ExceededSizeError rejects them, causing an additional allocation approximately proportional to the supplied token. Requests that exhaust available process memory can therefore cause an availability failure even though signature verification fails. This issue is fixed in version 1.7.6.