PT-2026-28602 · Clerk · @Clerk/Express+3

Highnikosdouvlis

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Published

2026-03-27

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Updated

2026-04-01

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CVE-2026-34076

CVSS v3.1

7.4

High

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Name of the Vulnerable Software and Affected Versions @clerk/backend versions 3.0.0 through 3.2.2 @clerk/express versions 2.0.0 through 2.0.6 @clerk/hono versions 0.1.0 through 0.1.4 @clerk/fastify versions 3.1.0 through 3.1.4
Description The clerkFrontendApiProxy function is susceptible to Server-Side Request Forgery (SSRF). An unauthenticated attacker can manipulate a request path to cause the proxy to transmit the application's Clerk-Secret-Key to a server controlled by the attacker. The vulnerability affects applications that have explicitly enabled the frontendApiProxy feature.
Recommendations Upgrade to @clerk/backend version 3.2.3 or later. Upgrade to @clerk/express version 2.0.7 or later. Upgrade to @clerk/hono version 0.1.5 or later. Upgrade to @clerk/fastify version 3.1.5 or later. Rotate your Clerk Secret Key after upgrading.

Fix

SSRF

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Weakness Enumeration

Related Identifiers

CVE-2026-34076
GHSA-GJXX-92W9-8V8F

Affected Products

@Clerk/Backend
@Clerk/Express
@Clerk/Fastify
@Clerk/Hono