CVE-2026-42073

Description

OpenClaude is an open-source coding-agent command line interface for cloud and local model providers. Prior to version 0.5.1, the OpenClaude MCP authentication flow starts a temporary local HTTP server to handle OAuth callbacks. To prevent CSRF attacks, the server validates a state parameter against an internally stored value. However, due to a logic flaw in the order of conditionals, an attacker can completely bypass this check and force the server to shut down — without knowing the state value at all. This issue has been patched in version 0.5.1.

Is your site exposed to CVE-2026-42073?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0022

Probability of exploitation

0.12%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-352 Cross-Site Request Forgery

CWE-400 Uncontrolled Resource Consumption

Affected Products

Vendor	Product	Versions
gitlawb	openclaude	< 0.5.1

References

Advisories & Patches

https://github.com/Gitlawb/openclaude/commit/739b8d1f40fde0e401a5cbd2b9a55d88bd5124ad https://github.com/Gitlawb/openclaude/security/advisories/GHSA-c73c-x77g-854r https://github.com/Gitlawb/openclaude/security/advisories/GHSA-c73c-x77g-854r

Exploits

https://github.com/Gitlawb/openclaude/security/advisories/GHSA-c73c-x77g-854r https://github.com/Gitlawb/openclaude/security/advisories/GHSA-c73c-x77g-854r

Other References

https://github.com/Gitlawb/openclaude/releases/tag/v0.5.1

Frequently Asked Questions

What is CVE-2026-42073? +

OpenClaude is an open-source coding-agent command line interface for cloud and local model providers. Prior to version 0.5.1, the OpenClaude MCP authentication flow starts a temporary local HTTP server to handle OAuth callbacks. To prevent CSRF attacks, the server validates a state parameter against an internally stored value. However, due to a logic flaw in the order of conditionals, an attacker can completely bypass this check and force the server to shut down — without knowing the state value at all. This issue has been patched in version 0.5.1. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-42073? +

CVE-2026-42073 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0022, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-42073? +

CVE-2026-42073 affects products from gitlawb, specifically: openclaude. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-42073? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-40325

Masa CMS is a content management system forked from Mura CMS. In versions 7.5.2 and earlier, the `cTrash.restore` function does …

CVE-2026-40174

Masa CMS is a content management system forked from Mura CMS. In versions 7.5.2 and earlier, the cUsers.updateAddress function does …

CVE-2024-6662

Websites managed by MegaBIP in versions below 5.15 are vulnerable to Cross-Site Request Forgery (CSRF) as the form available under …

CVE-2026-42286

Emlog is an open source website building system. Prior to version 2.6.11, missing CSRF protection in critical admin functions allows …

CVE-2026-9591

Cross-site request forgery (CSRF) in NewsItemApiController in SimplCommerce prior to commit 6233d73e allows an unauthenticated remote attacker to create or …

CVE-2024-7141

Versions of Gliffy Online prior to versions 4.14.0-7 contains a Cross Site Request Forgery (CSRF) flaw.