--- title: "CVE-2026-91156: Discourse - Broken Access Control" description: "Discourse < 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9 contains an information disclosure caused by improper enforcement of Chat eligibility in MessageBus audience calculation, letting authenticated users access restricted live and recent chat messages, exploit requires user to be authenticated and have category view permissions." url: https://panop.io/threat-heartbeat/CVE-2026-91156/ --- # CVE-2026-91156 Discourse - Broken Access Control Discourse < 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9 contains an information disclosure caused by improper enforcement of Chat eligibility in MessageBus audience calculation, letting authenticated users access restricted live and recent chat messages, exploit requires user to be authenticated and have category view permissions. CVSS base score 7.5 /10 High CISA KEV Not listed Public exploit None known Authentication Not required [View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-91156) ## Details Type Broken Access Control Impact Information Disclosure CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Published 14 October 2026 Updated 15 October 2026 Weakness [CWE-862](https://cwe.mitre.org/data/definitions/862.html) ## Vendor fix Update to versions 2026.9.0, 2026.8.1, 2026.7.3, or 2026.1.9. 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-2026-91156](https://nvd.nist.gov/vuln/detail/CVE-2026-91156) - [https://github.com/discourse/discourse/security/advisories/GHSA-gh4f-qr62-vx8q](https://github.com/discourse/discourse/security/advisories/GHSA-gh4f-qr62-vx8q) - [https://github.com/discourse/discourse/commit/046fb7bfd68a5b95e63dda88c3c73877c5cf9d5e](https://github.com/discourse/discourse/commit/046fb7bfd68a5b95e63dda88c3c73877c5cf9d5e) - [https://github.com/discourse/discourse/commit/87b31bf60a7827f075634254379a1dcbaba409cb](https://github.com/discourse/discourse/commit/87b31bf60a7827f075634254379a1dcbaba409cb) - [https://github.com/discourse/discourse/commit/ba74bb404ab4439f5b1f0204e848d62099db8ae1](https://github.com/discourse/discourse/commit/ba74bb404ab4439f5b1f0204e848d62099db8ae1) - [https://github.com/discourse/discourse/commit/cac1f26f275cec3dc1dd51dfdac2b3d1a4ec50f8](https://github.com/discourse/discourse/commit/cac1f26f275cec3dc1dd51dfdac2b3d1a4ec50f8) [← All CVEs](https://panop.io/threat-heartbeat/) ## 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 Panop answers these inside your environment, for this CVE and every other finding. [Book a demo](https://panop.io/demo)