CVE-2025-30204

CVE-2025-30204 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-405.

Key facts

Description

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.

Frequently asked questions

What is CVE-2025-30204?
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.
How severe is CVE-2025-30204?
CVE-2025-30204 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-30204 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-30204?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-30204 have an EU (EUVD) identifier?
Yes. CVE-2025-30204 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-7207.
When was CVE-2025-30204 published?
CVE-2025-30204 was published on 2025-03-21 and last updated on 2026-06-17.

References

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