6.9
MediumCVSS 4.0 · from GitHub_M
CVE-2026-119284
joserfc: Compact JWS size guard allocates attacker-controlled segments before rejection
joserfc · Uncontrolled resource use · CWE-400Affectedjoserfc
FixNo fix listed yet.
PublishedOct 29, 21:33 · GitHub_M
ScoredOct 29 · 6.9 · GitHub_M
Exploit code publicNone known · checked 21:18 UTC
ExploitedNone known · CISA KEV checked 22:09 UTC
What we know
No known exploitation. CISA KEV, checked 22:09 UTC.
No public exploit code known. Exploit-DB, Metasploit, Nuclei, checked 21:18 UTC.
An attacker only needs network access to the target. No login needed. CVSS: network, no privileges.
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.
From GitHub_M
Affected and fixed versions
ProductAffectedFixed injoserfc< 1.7.6–
Exploit code
Exploit-DBnone knownMetasploitnone knownNucleinone known