CVE-2025-30204 – github.com/golang-jwt/jwt/v5

Package

Manager: go
Name: github.com/golang-jwt/jwt/v5
Vulnerable Version: >=5.0.0-rc.1 <5.2.2

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00043 pctl0.1225

Details

jwt-go allows excessive memory allocation during header parsing ### Summary Function [`parse.ParseUnverified`](https://github.com/golang-jwt/jwt/blob/c035977d9e11c351f4c05dfeae193923cbab49ee/parser.go#L138-L139) currently splits (via a call to [strings.Split](https://pkg.go.dev/strings#Split)) its argument (which is untrusted data) on periods. As a result, in the face of a malicious request whose _Authorization_ header consists of `Bearer ` followed by many period characters, a call to that function incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. Relevant weakness: [CWE-405: Asymmetric Resource Consumption (Amplification)](https://cwe.mitre.org/data/definitions/405.html) ### Details See [`parse.ParseUnverified`](https://github.com/golang-jwt/jwt/blob/c035977d9e11c351f4c05dfeae193923cbab49ee/parser.go#L138-L139) ### Impact Excessive memory allocation

Metadata

Created: 2025-03-21T22:04:00Z
Modified: 2025-04-10T13:02:34Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/03/GHSA-mh63-6h87-95cp/GHSA-mh63-6h87-95cp.json
CWE IDs: ["CWE-405"]
Alternative ID: GHSA-mh63-6h87-95cp
Finding: F002
Auto approve: 1