CVE-2026-119284 Details
Description
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.
A denial-of-service vulnerability has been identified in the joserfc library, specifically in versions prior to 1.7.6. The issue arises in the deserialization of compact JSON Web Signatures (JWS). The library fails to validate the size of the compact serialization segments before splitting them, allowing attacker-controlled data to create oversized copies of the header, payload, and signature. This exploitation can lead to excessive memory allocation, causing processes to run out of available memory and fail, even though the signature verification itself would fail. The vulnerability is present in joserfc versions through 1.7.4.
Users can upgrade to joserfc version 1.7.6 or later, where this vulnerability has been fixed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 29, 2026CISA-ADP
Assessed Oct 30, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/authlib/joserfc/security/advisories/GHSA-9pg5-8c7x-5hfx | CISA-ADP | AdvisoryExploitRemedyVendor |
| https://github.com/authlib/joserfc/commit/397e04f4bbce0b94d86e31c1c003f4640af8fb39 | [email protected] | Source CodeVendor |
| https://github.com/authlib/joserfc/releases/tag/1.7.6 | [email protected] | Release NotesVendor |
| https://github.com/authlib/joserfc/security/advisories/GHSA-9pg5-8c7x-5hfx | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-400 | Uncontrolled Resource Consumption | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| authlib joserfc | <= 1.7.4 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 30, 2026 | CVE Modified | CISA-ADP |
| Oct 29, 2026 | New CVE Received | [email protected] |