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CVE-2025-30204

jwt-go allows excessive memory allocation during header parsing

### SummaryFunction [`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)### DetailsSee [`parse.ParseUnverified`](https://github.com/golang-jwt/jwt/blob/c035977d9e11c351f4c05dfeae193923cbab49ee/parser.go#L138-L139) ### ImpactExcessive memory allocation

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Vulnerability Details
Score
7.5
Score Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Versions
github.com/golang-jwt/jwt/v5 >= 5.0.0-rc.1 < 5.2.2; github.com/golang-jwt/jwt/v4 < 4.5.2; github.com/golang-jwt/jwt >= 3.2.0
Severity
High
Ecosystem
GO
Publish Date
March 21, 2025
Modified Date
April 10, 2025