# CVE-2026-42349: Clerk: Authorization bypass when combining organization, billing, or reverification checks > Attackers can bypass combined authorization checks in Clerk SDKs, allowing unauthorized access to gated actions when specific conditions are met. - **Severity:** High 7.6 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 11 May 2026 - **Updated:** 14 May 2026 - **Also known as:** GHSA-w24r-5266-9c3c ## What is CVE-2026-42349? CVE-2026-42349 is a high-severity authentication bypass vulnerability in @clerk astro, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description Clerk JavaScript is the official JavaScript repository for Clerk authentication. has(), auth.protect(), and related authorization predicates in @clerk/shared, @clerk/nextjs, @clerk/backend, and other framework SDKs can return true for certain combined authorization checks when the result should be false, allowing a gated action to proceed for a user who does not satisfy the full set of requested conditions. This call shape can be bypassed if certain conditions are met: a has() or auth.protect() call that combines a reverification check with any of role, permission, feature, or plan, or that combines a billing check (feature or plan) with a role or permission check. This vulnerability is fixed in @clerk/clerk-js 5.125.10 and 6.7.5. Weakness: CWE-863 (Incorrect Authorization), CWE-754 (Improper Check for Unusual or Exceptional Conditions) ## Which versions are affected by CVE-2026-42349? 40 open source packages ship an affected version, including @clerk/astro, @clerk/backend and @clerk/chrome-extension. It affects 17 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `@clerk/astro` | npm | From 2.0.0 | 2.17.11 | | `@clerk/astro` | npm | From 2.0.0 | 2.17.11 | | `@clerk/astro` | npm | From 3.0.0 | 3.0.18 | | `@clerk/astro` | npm | From 3.0.0 | 3.0.18 | | `@clerk/backend` | npm | From 2.0.0 | 2.33.3 | | `@clerk/backend` | npm | From 2.0.0 | 2.33.3 | | `@clerk/backend` | npm | From 3.0.0 | 3.2.14 | | `@clerk/backend` | npm | From 3.0.0 | 3.2.14 | | `@clerk/chrome-extension` | npm | From 1.3.5 | 2.9.15 | | `@clerk/chrome-extension` | npm | From 1.3.5 | 2.9.15 | | `@clerk/chrome-extension` | npm | From 3.0.0 | 3.1.15 | | `@clerk/chrome-extension` | npm | From 3.0.0 | 3.1.15 | | `@clerk/clerk-expo` | npm | From 2.2.11 | 2.19.36 | | `@clerk/clerk-expo` | npm | From 2.2.11 | 2.19.36 | | `@clerk/clerk-js` | npm | From 5.22.0 | 5.125.10 | | `@clerk/clerk-js` | npm | From 5.22.0 | 5.125.10 | | `@clerk/clerk-js` | npm | From 6.0.0 | 6.7.5 | | `@clerk/clerk-js` | npm | From 6.0.0 | 6.7.5 | | `@clerk/clerk-react` | npm | From 5.9.0 | 5.61.6 | | `@clerk/clerk-react` | npm | From 5.9.0 | 5.61.6 | | `@clerk/expo` | npm | From 3.0.0 | 3.2.2 | | `@clerk/expo` | npm | From 3.0.0 | 3.2.2 | | `@clerk/express` | npm | From 0.1.0 | 1.7.79 | | `@clerk/express` | npm | From 0.1.0 | 1.7.79 | | `@clerk/express` | npm | From 2.0.0 | 2.1.6 | | `@clerk/express` | npm | From 2.0.0 | 2.1.6 | | `@clerk/fastify` | npm | From 1.0.42 | 2.6.31 | | `@clerk/fastify` | npm | From 1.0.42 | 2.6.31 | | `@clerk/fastify` | npm | From 3.0.0 | 3.1.16 | | `@clerk/fastify` | npm | From 3.0.0 | 3.1.16 | | `@clerk/hono` | npm | From 0.0.2 | 0.1.16 | | `@clerk/hono` | npm | From 0.0.2 | 0.1.16 | | `@clerk/nextjs` | npm | From 6.0.0 | 6.39.3 | | `@clerk/nextjs` | npm | From 6.0.0 | 6.39.3 | | `@clerk/nextjs` | npm | From 7.0.0 | 7.2.4 | | `@clerk/nextjs` | npm | From 7.0.0 | 7.2.4 | | `@clerk/nuxt` | npm | From 1.0.0 | 1.13.29 | | `@clerk/nuxt` | npm | From 1.0.0 | 1.13.29 | | `@clerk/nuxt` | npm | From 2.0.0 | 2.2.5 | | `@clerk/nuxt` | npm | From 2.0.0 | 2.2.5 | Products: Clerk Clerk\/Astro, Clerk Clerk\/Backend, Clerk Clerk\/Chrome-Extension, Clerk Clerk\/Clerk-Expo, Clerk Clerk\/Clerk-Js, Clerk Clerk\/Clerk-React, Clerk Clerk\/Expo, Clerk Clerk\/Express, Clerk Clerk\/Fastify, Clerk Clerk\/Hono, Clerk Clerk\/Nextjs, Clerk Clerk\/Nuxt, Clerk Clerk\/React, Clerk Clerk\/React-Router, Clerk Clerk\/Shared, Clerk Clerk\/Tanstack-React-Start, Clerk Clerk\/Vue. ## How do I fix CVE-2026-42349? Upgrade @clerk/astro to a fixed version for your release line: 2.17.11 or 3.0.18. ## Is CVE-2026-42349 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42349 exists. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-42349 and fix it if it is affected. What it is: CVE-2026-42349 is a high-severity authentication bypass vulnerability in @clerk astro, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42349 exists. Affected packages and fixed versions: - @clerk/astro (npm): affected from 2.0.0; fixed in 2.17.11 - @clerk/astro (npm): affected from 2.0.0; fixed in 2.17.11 - @clerk/astro (npm): affected from 3.0.0; fixed in 3.0.18 - @clerk/astro (npm): affected from 3.0.0; fixed in 3.0.18 - @clerk/backend (npm): affected from 2.0.0; fixed in 2.33.3 - @clerk/backend (npm): affected from 2.0.0; fixed in 2.33.3 - @clerk/backend (npm): affected from 3.0.0; fixed in 3.2.14 - @clerk/backend (npm): affected from 3.0.0; fixed in 3.2.14 - @clerk/chrome-extension (npm): affected from 1.3.5; fixed in 2.9.15 - @clerk/chrome-extension (npm): affected from 1.3.5; fixed in 2.9.15 - @clerk/chrome-extension (npm): affected from 3.0.0; fixed in 3.1.15 - @clerk/chrome-extension (npm): affected from 3.0.0; fixed in 3.1.15 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-42349/ (Markdown: https://insights.sbomify.com/CVE-2026-42349/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42349 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42349 - OSV: https://osv.dev/vulnerability/CVE-2026-42349 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-42349/ Summaries are generated and may contain mistakes; the official description above is the record.