CVE-2026-45363

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Source
https://cve.org/CVERecord?id=CVE-2026-45363
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45363.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-45363
Aliases
Downstream
Related
Published
2026-07-14T21:32:26.676Z
Modified
2026-07-17T03:41:37.579912362Z
Severity
  • 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
`jwt` (Ruby gem) - empty-key HMAC bypass
Details

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 keyfinder: 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#verifysignature!. This issue is fixed in versions 2.10.3 and 3.2.0.

Database specific 
{
    "cwe_ids": [
        "CWE-1391",
        "CWE-287",
        "CWE-326"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45363.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/jwt/ruby-jwt

Affected ranges

Type
GIT
Repo
https://github.com/jwt/ruby-jwt
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Introduced
b987a5152732ab43d9e16558d3343ffca4c36cb1
Fixed
a52e81d2c6b6aa6ff4be929dfa69da6b52db2888
Fixed
db560b769a07bd9724e77ff505011ac01872106f
Fixed
9820020869ad147b941e49d96ab8beba35532964
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "2.10.3"
        },
        {
            "introduced": "3.0.0"
        },
        {
            "fixed": "3.2.0"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "REFERENCES"
    ]
}

Affected versions

jwt-0.*
jwt-0.1.10
jwt-0.1.11
jwt-0.1.3
jwt-0.1.4
jwt-0.1.5
jwt-0.1.6
jwt-0.1.7
jwt-0.1.8
jwt-1.*
jwt-1.0.0
jwt-1.2.0
jwt-1.2.1
jwt-1.3.0
jwt-1.4.0
jwt-1.4.1
jwt-1.5.1
jwt-1.5.2
v1.*
v1.5.3
v1.5.4
v1.5.5
v1.5.6
v2.*
v2.0.0
v2.0.0.beta1
v2.1.0
v2.10.0
v2.10.1
v2.10.2
v2.2.0
v2.2.0.pre.beta.0
v2.2.1
v2.2.2
v2.2.3
v2.3.0
v2.4.0.beta1
v2.4.1
v2.5.0
v2.6.0
v2.7.0
v2.7.1
v2.8.0
v2.8.1
v2.8.2
v2.9.0
v2.9.2
v2.9.3
v3.*
v3.0.0
v3.1.0
v3.1.1
v3.1.2

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45363.json"