---
title: "CVE-2026-91122: Discourse - Stored XSS"
description: "Discourse < 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0 contains a stored XSS caused by crafted HTML in the video placeholder component allowing attribute breakout and event handler injection, letting authenticated users with default trust-level execute arbitrary JavaScript in other users' sessions, exploit requires authenticated user with posting privileges."
url: https://panop.io/threat-heartbeat/CVE-2026-91122/
---

# CVE-2026-91122 Discourse - Stored XSS

Discourse < 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0 contains a stored XSS caused by crafted HTML in the video placeholder component allowing attribute breakout and event handler injection, letting authenticated users with default trust-level execute arbitrary JavaScript in other users' sessions, exploit requires authenticated user with posting privileges.

CVSS base score 8.7 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.26% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-91122)

## Details

Type

Stored XSS

Impact

Client Script Exec, Information Disclosure

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Published

24 September 2026

Updated

15 October 2026

Weakness

[CWE-79](https://cwe.mitre.org/data/definitions/79.html)

## Vendor fix

Update to versions 2026.1.8, 2026.6.3, 2026.7.2, or 2026.8.0.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-91122](https://nvd.nist.gov/vuln/detail/CVE-2026-91122)
- [https://github.com/discourse/discourse/commit/05d92b8749f68d2626cbe65ec7adde7562a0283d](https://github.com/discourse/discourse/commit/05d92b8749f68d2626cbe65ec7adde7562a0283d)
- [https://github.com/discourse/discourse/commit/5674b3e6594825c28d2678e55057fd6802f11031](https://github.com/discourse/discourse/commit/5674b3e6594825c28d2678e55057fd6802f11031)
- [https://github.com/discourse/discourse/commit/c3993e318e172389be5c98455177876f1dd87dda](https://github.com/discourse/discourse/commit/c3993e318e172389be5c98455177876f1dd87dda)
- [https://github.com/discourse/discourse/commit/d7126af3264b672d2201d84c18a37cb8627424a8](https://github.com/discourse/discourse/commit/d7126af3264b672d2201d84c18a37cb8627424a8)
- [https://github.com/discourse/discourse/pull/42882](https://github.com/discourse/discourse/pull/42882)
- [https://github.com/discourse/discourse/security/advisories/GHSA-8m44-f6g9-7cg7](https://github.com/discourse/discourse/security/advisories/GHSA-8m44-f6g9-7cg7)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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