Appwrite up to 1.1.2 Webhook Verification github.js verifyWebhook improper authentication

Summaryinfo

A vulnerability was found in Appwrite up to 1.1.2. It has been rated as problematic. Affected by this vulnerability is the function verifyWebhook of the file node/github-issue-bot/src/github.js of the component Webhook Verification. Performing a manipulation results in improper authentication. This vulnerability is known as CVE-2026-72861. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Appwrite up to 1.1.2. It has been classified as problematic. This affects the function verifyWebhook of the file node/github-issue-bot/src/github.js of the component Webhook Verification. The manipulation with an unknown input leads to a improper authentication vulnerability. CWE is classifying the issue as CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. This is going to have an impact on integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-72861 since 08/10/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/20/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• Appwrite

Version

• 1.1.0
• 1.1.1
• 1.1.2

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Be aware that VulDB is the high quality source for vulnerability data.

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