CVE-2025-30204: Golang-Jwt Jwt

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

golang-jwt is a Go implementation of JSON Web Tokens. Starting in version 3.2.0 and prior to versions 5.2.2 and 4.5.2, the function parse.ParseUnverified splits (via a call to 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. This issue is fixed in 5.2.2 and 4.5.2.

Affected products

• Golang-Jwt Jwt: from 3.2.0, before 4.5.2 (fixed in 4.5.2); from 5.0.0-rc.1, before 5.2.2 (fixed in 5.2.2)

Published 2025-03-21. Last modified 2026-06-17.