---
id: CVE-2026-91122
title: Discourse is an open-source discussion platform
summary: >-
  Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3,
  2026.7.2, and 2026.8.0, the video placeholder component allowed crafted HTML
  to cause an attribute breakout and inject an attacker-controlled event
  handler. An…
severity: high
cvss: 8.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N'
cwe:
  - CWE-79
vendor: discourse
product: discourse
affected:
  - discourse < 2026.8.0
  - 'discourse >= 2026.7.0-latest, < 2026.7.2'
  - 'discourse >= 2026.6.0-latest, < 2026.6.3'
  - 'discourse >= 2026.1.0-latest, < 2026.1.8'
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T18:19:06.763'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91122'
references:
  - url: >-
      https://github.com/discourse/discourse/commit/05d92b8749f68d2626cbe65ec7adde7562a0283d
    label: security-advisories@github.com
  - url: >-
      https://github.com/discourse/discourse/commit/5674b3e6594825c28d2678e55057fd6802f11031
    label: security-advisories@github.com
  - url: >-
      https://github.com/discourse/discourse/commit/c3993e318e172389be5c98455177876f1dd87dda
    label: security-advisories@github.com
  - url: >-
      https://github.com/discourse/discourse/commit/d7126af3264b672d2201d84c18a37cb8627424a8
    label: security-advisories@github.com
  - url: 'https://github.com/discourse/discourse/pull/42882'
    label: security-advisories@github.com
  - url: >-
      https://github.com/discourse/discourse/security/advisories/GHSA-8m44-f6g9-7cg7
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-24T17:25:16.666454Z'
ingestedAt: '2026-09-24T17:48:30.386Z'
---

## Overview

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the video placeholder component allowed crafted HTML to cause an attribute breakout and inject an attacker-controlled event handler. An authenticated user with default trust-level posting privileges could store the crafted placeholder in a post. When another user opened the post and clicked the video play overlay, the handler could execute arbitrary JavaScript in the viewer's session. Default Content Security Policy settings block inline event handlers, but instances with CSP disabled or relaxed could allow the script to read page content and make authenticated requests as the viewer. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.