CVE-2026-119284 joserfc: Compact JWS size guard allocates attacker-controlled segments before rejection
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-119284?
CVE-2026-119284 is a medium-severity vulnerability in authlib joserfc, published on 29 Oct 2026.
Official 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.
Weakness: CWE-400
Which versions are affected by CVE-2026-119284?
How do I fix CVE-2026-119284?
No fix has been published for CVE-2026-119284 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-119284 being exploited?
There is no known exploitation of CVE-2026-119284 in the wild and no public exploit code.