CVE-2025-53548: @clerk/backend Performs Insufficient Verification of Data Authenticity

Published Jul 9, 2025
·
Updated

Impact

Applications that use the verifyWebhook() helper to verify incoming Clerk webhooks are susceptible to accepting improperly signed webhook events.

Patches

@clerk/backend: the helper has been patched as of 2.4.0 @clerk/astro: the helper has been patched as of 2.10.2 @clerk/express: the helper has been patched as of 1.7.4 @clerk/fastify: the helper has been patched as of 2.4.4 @clerk/nextjs: the helper has been patched as of 6.23.3 @clerk/nuxt: the helper has been patched as of 1.7.5 @clerk/react-router: the helper has been patched as of 1.6.4 @clerk/remix: the helper has been patched as of 4.8.5 @clerk/tanstack-react-start: the helper has been patched as of 0.18.3

Resolution

The issue was resolved in @clerk/backend 2.4.0 by:

Properly parsing the webhook request's signatures and comparing them against the signature generated from the received event

Workarounds

If unable to upgrade, developers can workaround this issue by verifying webhooks manually, per this documentation.

Other sources

Clerk helps developers build user management. Applications that use the verifyWebhook() helper to verify incoming Clerk webhooks are susceptible to accepting improperly signed webhook events. The issue was resolved in @clerk/backend 2.4.0.

— MITRE

Affected Software

10 affected componentsFixes available
Clerk @clerk/backend<2.4.0
npm/@clerk/tanstack-react-start>=0.16.0<0.18.3
0.18.3
npm/@clerk/remix>=4.8.0<4.8.5
4.8.5
npm/@clerk/react-router>=1.5.0<1.6.4
1.6.4
npm/@clerk/nuxt>=1.7.0<1.7.5
1.7.5
npm/@clerk/nextjs>=6.2.10<6.23.3
6.23.3
npm/@clerk/fastify>=2.3.0<2.4.4
2.4.4
npm/@clerk/express>=1.6.0<1.7.4
1.7.4
npm/@clerk/astro>=2.9.0<2.10.2
2.10.2
npm/@clerk/backend>=2.0.0<2.4.0
2.4.0

Event History

Jul 9, 2025
CVE Published
via MITRE·05:12 PM
Data Sourced
via MITRE·05:12 PM
DescriptionSeverityWeakness
Advisory Published
via GitHub·06:07 PM
Data Sourced
via GitHub·06:07 PM
DescriptionSeverityWeaknessAffected Software
Data Sourced
via NVD·06:15 PM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2025-53548?

CVE-2025-53548 is classified as a critical severity vulnerability due to its potential to facilitate unauthorized access via improperly signed webhooks.

2

How do I fix CVE-2025-53548?

To fix CVE-2025-53548, upgrade to version 2.4.0 or later of the @clerk/backend package.

3

What applications are affected by CVE-2025-53548?

CVE-2025-53548 affects applications using the verifyWebhook() helper in the @clerk/backend package prior to version 2.4.0.

4

How can I verify if my application is impacted by CVE-2025-53548?

Check if your application uses the @clerk/backend package with a version lower than 2.4.0 and utilizes the verifyWebhook() helper.

5

What potential risks are associated with CVE-2025-53548?

The risks include accepting fraudulent webhook events, which could lead to unauthorized actions within your application.

Company

Resources

Contact

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