GHSA-w5cr-2qhr-jqc5

Source

https://github.com/advisories/GHSA-w5cr-2qhr-jqc5

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-w5cr-2qhr-jqc5/GHSA-w5cr-2qhr-jqc5.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-w5cr-2qhr-jqc5

Published

2026-02-13T21:04:00Z

Modified

2026-02-13T21:10:51Z

Severity

6.2 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N CVSS Calculator

Summary

Cloudflare Agents has a Reflected Cross-Site Scripting (XSS) vulnerability in AI Playground site

Details

Summary

A Reflected Cross-Site Scripting (XSS) vulnerability was discovered in the AI Playground's OAuth callback handler. The error_description query parameter was directly interpolated into an HTML script tag without proper escaping, allowing attackers to execute arbitrary JavaScript in the context of the victim's session.

Root cause

The OAuth callback handler in site/ai-playground/src/server.ts directly interpolated the authError value, sourced from the error_description query parameter, into an inline <script> tag.

Impact

An attacker could craft a malicious link that, when clicked by a victim, would:

Steal user chat message history
Access all LLM interactions stored in the user's session.
Access connected MCP Servers
Interact with any MCP servers connected to the victim's session (public or authenticated/private), potentially allowing the attacker to perform actions on the victim's behalf

Mitigation:

PR: https://github.com/cloudflare/agents/pull/841
Agents-sdk users should upgrade to agents@0.3.10
Developers using configureOAuthCallback with custom error handling in their own applications should ensure all user-controlled input is escaped before interpolation.

Credits

Disclosed responsibly by Nishant Kumawat

Database specific

{
    "cwe_ids":  [
        "CWE-79"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-02-13T21:04:00Z",
    "nvd_published_at":  null,
    "severity":  "MODERATE"
}

References

Affected packages

npm / agents

Package

Name: agents; View open source insights on deps.dev
Purl: pkg:npm/agents

Affected ranges

Type: SEMVER
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

0.3.10

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-w5cr-2qhr-jqc5/GHSA-w5cr-2qhr-jqc5.json"