# CVE-2026-72861: Appwrite Templates github-issue-bot Skips Webhook Signature Verification When the X-Hub-Signature-256 Header Is Absent

> CVE-2026-72861: Appwrite Templates github-issue-bot Skips Webhook Signature Verification When the X-Hub-Signature-256 Header Is Absent. CVSS 5.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-72861
Last updated: 2026-10-18T20:10:00Z

- Published: 2026-08-20 19:48 UTC · Updated: 2026-10-18 20:10 UTC · Assigner: VulnCheck
- CVSS: 5.8 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- EPSS: 0.27%, 19th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-347

## Description

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.

## Affected vendors and products

- appwrite: templates

## Tracked companies

- [Appwrite](https://rewindex.com/company/appwrite.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-72861)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-72861)
- [https://github.com/appwrite/templates](https://github.com/appwrite/templates)
- [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/github.js)
- [https://github.com/appwrite/templates/blob/1.1.2/node/github-issue-bot/src/main.js](https://github.com/appwrite/templates/blob/1.1.2/node/github-issue-bot/src/main.js)
- [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-typescript/github-issue-bot/src/github.ts)
- [https://github.com/appwrite/templates/issues/350](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](https://www.vulncheck.com/advisories/appwrite-templates-github-issue-bot-skips-webhook-signature-verification-when-the-x-hub-signature-256-header-is-absent)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-72861 · Markdown: https://rewindex.com/cve/CVE-2026-72861.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-72861 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:06:17.306Z