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Vulnerability record · CVE-2026-79786 · published 25 August 2026

CVE-2026-79786: Open redirect vulnerability

Coroot's unauthenticated MCP OAuth dynamic client registration endpoint accepts any syntactically valid redirect URI without validation, allowing attackers to register clients pointing to attacker-controlled hosts. Attackers can send authorization URLs to signed-in users, capture their authorization codes upon consent approval, and exchange them for access tokens to hijack MCP sessions.

7.0 CVSS 4.0 High EPSS 0.27% · top 82.4% CWE-601 · Open redirect Deferred
7.0CVSS 4.0 base score
0.27%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
5References
23 Sep 2026Last modified by NVD

Description

Coroot's unauthenticated MCP OAuth dynamic client registration endpoint accepts any syntactically valid redirect URI without validation, allowing attackers to register clients pointing to attacker-controlled hosts. Attackers can send authorization URLs to signed-in users, capture their authorization codes upon consent approval, and exchange them for access tokens to hijack MCP sessions.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/coroot/coroot
https://github.com/coroot/coroot/blob/v1.24.5/api/mcp_oauth.go
https://github.com/coroot/coroot/issues/929
https://www.vulncheck.com/advisories/coroot-1.20.2-through-1.24.5-unvalidated-redirect-uri-in-mcp-oauth-client-registrat
https://github.com/coroot/coroot/issues/929

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

4.7CVE-2012-0518Oracle Fusion Middleware SSO open redirect flawOracle Fusion Middleware 10.1.4.3.0 contains an unspecified open redirect vulnerability in the Application Server Single Sign-On component, tracked a…KEVEPSS 4.7%analysed6.1CVE-2021-38000Google Chrome Android Intents input validation open redirectChrome on Android before 95.0.4638.69 fails to properly validate untrusted input passed through Intents, allowing a crafted HTML page to redirect the…KEVEPSS 4.9%analysed

Source: NIST National Vulnerability Database (record CVE-2026-79786), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.