CVE-2026-91133 (CVSS 6.5)

Description

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, authenticated users could supply unescaped SQL LIKE metacharacters to upload-resolution patterns, causing wildcard input to select unrelated upload records instead of matching a literal identifier. The affected upload metadata, URL-lookup, and cooked-video-placeholder paths could resolve uploads the user was not authorized to access. This allowed disclosure of restricted metadata, including original filenames and secure-upload paths, without modifying the upload records. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

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CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0029

Probability of exploitation

0.20%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-943 CWE-943

References

Other References

https://github.com/discourse/discourse/commit/113c34d433d564bc69642649d501251a7e820b52 https://github.com/discourse/discourse/commit/20c48bef712ee3edd4f7af58ca1123cb0c16ef6f https://github.com/discourse/discourse/commit/a04cab107a9f57939456181c4b082d0a34ec39bd https://github.com/discourse/discourse/commit/cb3ca8420fcc7aba334effd011cf41943a336fa6 https://github.com/discourse/discourse/pull/42882 https://github.com/discourse/discourse/security/advisories/GHSA-8hxh-573g-52gx

Frequently Asked Questions

What is CVE-2026-91133? +

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, authenticated users could supply unescaped SQL LIKE metacharacters to upload-resolution patterns, causing wildcard input to select unrelated upload records instead of matching a literal identifier. The affected upload metadata, URL-lookup, and cooked-video-placeholder paths could resolve uploads the user was not authorized to access. This allowed disclosure of restricted metadata, including original filenames and secure-upload paths, without modifying the upload records. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-91133? +

CVE-2026-91133 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0029, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-91133? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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