CVE-2025-30204Network attack vector

Service interruption via unbounded token splitting

Published Mar 21, 2025 · Updated Apr 10, 2025

Resource exhaustion in golang-jwt jwt 3.2.0 through 4.5.1 and 5.0.0-rc.1 through 5.2.1 allows remote attackers to interrupt services. Parser.ParseUnverified uses strings.Split on the entire untrusted token, allocating a slice entry for every period before rejecting extra segments. Any unauthenticated endpoint that passes a crafted Bearer token to this function can exhaust application memory and interrupt the hosting service.

CVSS severity7.5
High
EPSS probability0.72%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in golang-jwt jwt 3.2.0 through 4.5.1 and 5.0.0-rc.1 through 5.2.1 allows remote attackers to interrupt services. Parser.ParseUnverified uses strings.Split on the entire untrusted token, allocating a slice entry for every period before rejecting extra segments. Any unauthenticated endpoint that passes a crafted Bearer token to this function can exhaust application memory and interrupt the hosting service.

The record

CVE
CVE-2025-30204
Published
Mar 21, 2025
Updated
Apr 10, 2025
Vendor
golang-jwt
Product
jwt
Classifications
CWE-405, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 3.2.0, < 4.5.2
  2. Affected versionversion=>= 5.0.0-rc.1, < 5.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

golang-jwt · jwtversion=>= 3.2.0, < 4.5.2; version=>= 5.0.0-rc.1, < 5.2.2

Published CVSS scores

8.7GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5golang-jwtCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-405Asymmetric Resource Consumption (Amplification)
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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