Reflected cross-site scripting (XSS) In @grackle-ai/server

Description

@grackle-ai/server: Unescaped Error String in renderPairingPage() HTML Template

Impact

The renderPairingPage() function embeds the error parameter directly into HTML without escaping:

const errorHtml = error ? `<p style="color:#e74c3c">${error}</p>` : "";

All current call sites pass hardcoded strings, so this is not exploitable today. However, the function is architecturally fragile — if a future code change passes user-controlled or dynamic content into the error parameter, it would create an XSS vulnerability.

The renderAuthorizePage() function in the same file correctly uses escapeHtml() for dynamic content, making this an inconsistency.

Affected code:

    packages/server/src/index.ts:64-89renderPairingPage() with unescaped error interpolation

    Compare: packages/server/src/index.ts:130renderAuthorizePage() correctly uses escapeHtml()

Patches

v0.70.1

Fix: Apply escapeHtml() to the error parameter:

const errorHtml = error ? `<p style="color:#e74c3c">${escapeHtml(error)}</p>` : "";

Workarounds

No workaround needed — all current callers pass hardcoded strings.

Resources

    CWE-79: Improper Neutralization of Input During Web Page Generation

    File: packages/server/src/index.ts

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem
Package
Affected version
Patched versions