Answer in brief
CVE-2026-45363 records a Critical severity (CVSS 9.1) vulnerability in `jwt` (Ruby gem) - empty-key HMAC bypass. The current sources do not mark it as known exploited. The current feed maps jwt/ruby-jwt (generic), jwt (rubygems), jwt (rubygems). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps jwt/ruby-jwt (generic), jwt (rubygems), jwt (rubygems). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| jwt/ruby-jwtgeneric | <2.10.3 || >=3.0.0 <3.2.0 | 2.10.3, 3.2.0 |
| jwtrubygems | >=3.0.0 <3.2.0 | 3.2.0 |
| jwtrubygems | >=0 <2.10.3 | 2.10.3 |
Published upstream
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 15, 2026
ruby-jwt is a Ruby implementation of the RFC 7519 OAuth JSON Web Token standard. Prior to 2.10.3 and 3.2.0, JWT.decode(token, '', true, algorithm: 'HS256') accepts an attacker-forged token because OpenSSL::HMAC.digest('SHA256', '', payload) returns a valid digest under an empty key and no empty-key precondition exists in the HMAC algorithm. The same path is reached when a keyfinder block or key_finder: argument returns an empty string, nil, or an array containing nil for an unknown key, affecting HS256, HS384, and HS512 verification through JWT.decode and JWT::EncodedToken#verify_signature!. This issue is fixed in versions 2.10.3 and 3.2.0.
Quoted source text, attributed separately from HOL analysis.