# Clerk Backend vulnerabilities

Source: https://junglewise.ai/threats/technologies/backend  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 9 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/technologies/backend.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 3 vulnerabilities in Clerk Backend: 0 in the last 7 days and 0 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, CVE-2026-42349, was published on 11 May 2026.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 0
- All time: 3 (0 critical, 0 exploited in the wild)

## About Clerk Backend

Backend library for Clerk providing server-side authentication, session, and user management functionality.

## Latest Clerk Backend vulnerabilities

- [CVE-2026-42349: Clerk JavaScript SDKs authorization bypass in combined predicates](https://junglewise.ai/threats/cve-2026-42349-clerk-javascript-sdks-authorization-bypass-in-combined-predicates) (high, CVSS 8.1, published 11 May 2026)
- [CVE-2026-34076: Clerk backend SSRF in clerkFrontendApiProxy feature](https://junglewise.ai/threats/cve-2026-34076-clerk-backend-ssrf-in-clerkfrontendapiproxy-feature) (high, CVSS 7.4, published 1 Apr 2026)
- [CVE-2025-53548: Clerk webhook verifyWebhook insufficient signature verification](https://junglewise.ai/threats/cve-2025-53548-clerk-webhook-verifywebhook-insufficient-signature-verification) (low, CVSS 3.1, published 9 Jul 2025)

## Most severe Clerk Backend vulnerabilities

- [CVE-2026-42349: Clerk JavaScript SDKs authorization bypass in combined predicates](https://junglewise.ai/threats/cve-2026-42349-clerk-javascript-sdks-authorization-bypass-in-combined-predicates) (high, CVSS 8.1, published 11 May 2026)
- [CVE-2026-34076: Clerk backend SSRF in clerkFrontendApiProxy feature](https://junglewise.ai/threats/cve-2026-34076-clerk-backend-ssrf-in-clerkfrontendapiproxy-feature) (high, CVSS 7.4, published 1 Apr 2026)
- [CVE-2025-53548: Clerk webhook verifyWebhook insufficient signature verification](https://junglewise.ai/threats/cve-2025-53548-clerk-webhook-verifywebhook-insufficient-signature-verification) (low, CVSS 3.1, published 9 Jul 2025)

## Vulnerabilities per week

Nothing was published in the last eight weeks.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 0 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 0 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 0 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## Other Clerk technologies

- [Clerk Nextjs](https://junglewise.ai/threats/technologies/nextjs): 4 vulnerabilities

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "Clerk Backend vulnerabilities", https://junglewise.ai/threats/technologies/backend, 9 November 2026.