SEPTEMBER 18, 2026
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Case File

CVE-2026-72861

MEDIUM · CVSS 5.8 EPSS 0.20% Public Exploit

Source: NVD + CISA KEV + EPSS · Published 2026-08-20 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

The vulnerability affects the GitHub webhook signature verification in the GitHub issue bot templates, where an incorrect condition allows unauthenticated requests without a valid signature to be processed. This flaw can lead to unauthorized posting of comments on any repository and issue, potentially compromising sensitive information or disrupting workflows. Organizations using the GitHub issue bot should prioritize addressing this vulnerability to prevent exploitation and maintain the integrity of their repositories.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

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CVE
CVE-2026-72861
Severity
MEDIUM
CVSS
5.8
EPSS
0.20%
GitHub

Original NVD 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.