Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.

CVE-2026-91157 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

Discourse is an open-source discussion platform. Prior to 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9, sites with secure uploads enabled did not reconcile existing upload security metadata when a previously public category became read-restricted or when category permissions changed during a bulk import. Media and attachments uploaded while the category was public retained a public accessibility flag and remained reachable by anonymous users through their short upload URLs, including uploads associated with deleted topics. This issue is fixed in versions 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9.

Metrics

CVSS 3.x Severity and Vector Strings:

VolerionCVSS-B:3.7 LOWVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

CNA: [email protected]CVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URL	Source(s)	Tag(s)
https://github.com/discourse/discourse/commit/16017732981fdb3ee65d7b3c69c573610bf02aab	[email protected]	Source CodeVendor
https://github.com/discourse/discourse/commit/83f5f9f1df7ddc79ec0950e1b2038ba659635708	[email protected]	Source CodeVendor
https://github.com/discourse/discourse/commit/98f1c021d0e956cded5239a5d8a6afe2b9e1b7e7	[email protected]	Source CodeVendor
https://github.com/discourse/discourse/commit/b2fb98394b2636b29e850f06b0029f8ca8b48458	[email protected]	Source CodeVendor
https://github.com/discourse/discourse/security/advisories/GHSA-298h-xgw6-4pv3	[email protected]	AdvisoryRemedyVendor

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-200	Exposure of Sensitive Information to an Unauthorized Actor	[email protected]
CWE-863	Incorrect Authorization	[email protected]

Affected Products

Product	Versions
Discourse	>= 2026.8.0-latest (semver) >= 2026.7.0-latest (semver) >= 2026.1.0-latest (semver)
CPE cpe:2.3:a:discourse:discourse:::::::: Remediation Upgrade: 2026.9.0moderate effort Upgrade: 2026.8.1moderate effort Upgrade: 2026.7.3moderate effort Upgrade: 2026.1.9moderate effort Mitigation:low effort Download and re-upload the affected media through a restricted context, or delete the affected uploads from the server. Removing affected uploads from the Discourse storage location will prevent anonymous access.

Product

Versions

Discourse

>= 2026.8.0-latest (semver)

>= 2026.7.0-latest (semver)

>= 2026.1.0-latest (semver)

CPE

cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*

Remediation

Upgrade: 2026.9.0moderate effort
Upgrade: 2026.8.1moderate effort
Upgrade: 2026.7.3moderate effort
Upgrade: 2026.1.9moderate effort
Mitigation:low effort
Download and re-upload the affected media through a restricted context, or delete the affected uploads from the server. Removing affected uploads from the Discourse storage location will prevent anonymous access.

Change History

2 change records found show changes

Date	Action	Recorded By
Oct 20, 2026	CVE Modified	CISA-ADP
Oct 14, 2026	New CVE Received	[email protected]