CVE-2026-42349Network attack vector

Authenticated authorization bypass via misprocessed predicate options

Published May 11, 2026 · Updated May 11, 2026

Authorization bypass in Clerk JavaScript SDKs allows remote authenticated users to pass affected multi-condition access checks. The has(), auth.protect(), and createCheckAuthorization predicates return true for unsafe condition combinations; Next.js auth.protect() also discards authorization parameters when redirect or token options share the argument object. Exploitation requires an affected application to use one of these call shapes and permits only the gated action; authentication, sessions, impersonation, and token verification remain unaffected.

CVSS severity8.1
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in Clerk JavaScript SDKs allows remote authenticated users to pass affected multi-condition access checks. The has(), auth.protect(), and createCheckAuthorization predicates return true for unsafe condition combinations; Next.js auth.protect() also discards authorization parameters when redirect or token options share the argument object. Exploitation requires an affected application to use one of these call shapes and permits only the gated action; authentication, sessions, impersonation, and token verification remain unaffected.

The record

CVE
CVE-2026-42349
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Clerk
Product
@clerk/backend
Classifications
CWE-754, CWE-863, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 11, 2026CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 2.0.0, <= 2.33.2
  2. Affected versionversion=>= 3.0.0, <= 3.2.13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Clerk · @clerk/backendversion=>= 2.0.0, <= 2.33.2; version=>= 3.0.0, <= 3.2.13
Clerk · @clerk/sharedversion=>= 3.0.0, <= 3.47.4; version=>= 4.0.0, <= 4.8.2
Clerk · @clerk/react-routerversion=>= 0.0.1, <= 2.4.12; version=>= 3.0.0, <= 3.1.3
Clerk · @clerk/chrome-extensionversion=>= 1.3.5, <= 2.9.14; version=>= 3.0.0, <= 3.1.14
Clerk · @clerk/nextjsversion=>= 6.0.0, <= 6.39.2; version=>= 7.0.0, <= 7.2.3
Clerk · @clerk/vueversion=>= 1.0.0, <= 1.17.20; version=>= 2.0.0, <= 2.0.15
Clerk · @clerk/nuxtversion=>= 1.0.0, <= 1.13.28; version=>= 2.0.0, <= 2.2.4
Clerk · @clerk/tanstack-react-startversion=>= 0.0.1, <= 0.29.10; version=>= 1.0.0, <= 1.1.3
Clerk · @clerk/honoversion=>= 0.0.2, <= 0.1.15
Clerk · Clerk JavaScript SDKversion=>= 5.22.0, < 5.125.10; version=>= 6.0.0, < 6.7.5
Clerk · @clerk/reactversion=>= 5.9.0, <= 5.61.5; version=>= 6.0.0, <= 6.4.2
Clerk · @clerk/astroversion=>= 2.0.0, <= 2.17.10; version=>= 3.0.0, <= 3.0.17
Clerk · @clerk/fastifyversion=>= 1.0.42, <= 2.6.30; version=>= 3.0.0, <= 3.1.15
Clerk · @clerk/expressversion=>= 0.1.0, <= 1.7.78; version=>= 2.0.0, <= 2.1.5
Clerk · @clerk/expoversion=>= 2.2.11, <= 2.19.35; version=>= 3.0.0, <= 3.2.1

Published CVSS scores

8.1NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
7.6GitHubCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
CWE-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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