The github-issue-bot templates in appwrite/templates verify the GitHub webhook signature with an inverted condition. verifyWebhook in node/github-issue-bot/src/github.js and in node-typescript/github-issue-bot/src/github.ts returns "typeof signature !== 'string' || (await verify(...))", so when the X-Hub-Signature-256 header is absent the first operand is true, the logical OR short-circuits, and the function reports success without performing any HMAC verification. main.js rejects a request only when verifyWebhook returns false, so an unauthenticated request carrying no signature passes the check. Processing then continues to postComment, which takes the repository and issue objects directly from the request body, letting the caller direct the deployed function to post a comment on a repository and issue of their choosing using the configured GITHUB_TOKEN, with the issue author login from the body interpolated into the comment text.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 6.9NVD modified 2026-10-18 20:10
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 6
- https://github.com/appwrite/templates
- https://github.com/appwrite/templates/blob/1.1.2/node-typescript/github-issue-bot/src/github.ts
- https://github.com/appwrite/templates/blob/1.1.2/node/github-issue-bot/src/github.js
- https://github.com/appwrite/templates/blob/1.1.2/node/github-issue-bot/src/main.js
- https://github.com/appwrite/templates/issues/350
- https://www.vulncheck.com/advisories/appwrite-templates-github-issue-bot-skips-webhook-signature-verification-when-the-x-hub-signature-256-header-is-absent