CVE-2026-45363
Received
Received - Intake
BaseFortify
Vulnerability report for CVE-2026-45363, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-07-14
Last updated on: 2026-07-14
Assigner: GitHub, Inc.
Description
Description
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| jwt | ruby-jwt | 2.10.3 |
| jwt | ruby-jwt | 3.2.0 |
| jwt | ruby-jwt | to 2.10.3 (exc) |
| jwt | ruby-jwt | to 3.2.0 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-1391 | The product uses weak credentials (such as a default key or hard-coded password) that can be calculated, derived, reused, or guessed by an attacker. |
| CWE-287 | When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. |
| CWE-326 | The product stores or transmits sensitive data using an encryption scheme that is theoretically sound, but is not strong enough for the level of protection required. |
