CVE-2026-91123

The open-source discussion platform Discourse is vulnerable to an iframe src traversal issue in versions prior to 2026.1.8 , 2026.6.3 , 2026.7.2 , and 2026.8.0 . The root cause is that the iframe src traversal guard fails to treat literal backslashes as path separators following decoded dot segme...

EUVD-2026-86300

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the iframe src traversal guard did not treat literal backslashes as path separators after decoded dot segments. A crafted source could therefore pass an allowediframes subpath check while browser...

CVE-2026-91123 Discourse: Reject literal backslash path separators in iframe src traversal guard

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the iframe src traversal guard did not treat literal backslashes as path separators after decoded dot segments. A crafted source could therefore pass an allowediframes subpath check while browser...

CVE-2026-91123 Discourse: Reject literal backslash path separators in iframe src traversal guard

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the iframe src traversal guard did not treat literal backslashes as path separators after decoded dot segments. A crafted source could therefore pass an allowediframes subpath check while browser...

CVE-2026-91133

The open-source discussion platform Discourse is vulnerable to an information disclosure flaw in versions prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0 . Authenticated users can provide unescaped SQL LIKE metacharacters in upload-resolution patterns. This allows wildcard input to select unr...

EUVD-2026-86299

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 identifie...

CVE-2026-91133 Discourse: Escape LIKE metacharacters in upload paths to prevent disclosure

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 identifie...

CVE-2026-91133 Discourse: Escape LIKE metacharacters in upload paths to prevent disclosure

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 identifie...

CVE-2026-91133 Discourse: Escape LIKE metacharacters in upload paths to prevent disclosure

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 identifie...

CVE-2026-91134 Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowediframes prefix policy when the iframe src contained encoded userinfo. The sanitizer validated a decoded form...

CVE-2026-91134

The open-source discussion platform Discourse contains a vulnerability in its post sanitizer prior to versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0 . The root cause is a logic flaw where the sanitizer validates a decoded form of an iframe src differently than how the browser interprets it. ...

EUVD-2026-86298

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowediframes prefix policy when the iframe src contained encoded userinfo. The sanitizer validated a decoded form...

CVE-2026-91134 Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowediframes prefix policy when the iframe src contained encoded userinfo. The sanitizer validated a decoded form...

CVE-2026-91134 Discourse: Block post iframes whose encoded userinfo bypasses the allowed_iframes allowlist

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the Discourse post sanitizer allowed a stored cross-origin iframe to bypass the allowediframes prefix policy when the iframe src contained encoded userinfo. The sanitizer validated a decoded form...

CVE-2026-84302 Discourse: Non-participant moderators can read, edit, and delete PM content through Discourse AI reviewables

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did n...

CVE-2026-84302

The open-source discussion platform Discourse is vulnerable in versions prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0 . The root cause is that reviewable visibility filtering fails to restrict Discourse AI reviewables associated with private messages. This allows moderators who are not part...

CVE-2026-84302 Discourse: Non-participant moderators can read, edit, and delete PM content through Discourse AI reviewables

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did n...

EUVD-2026-86297

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did n...

CVE-2026-84302 Discourse: Non-participant moderators can read, edit, and delete PM content through Discourse AI reviewables

Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Discourse AI reviewables associated with private messages could appear in the moderator review queue of a moderator who was not a participant in the message. Reviewable visibility filtering did n...

PT-2026-98154

Name of the Vulnerable Software and Affected Versions Discourse versions prior to 2026.1.8 Discourse versions prior to 2026.6.3 Discourse versions prior to 2026.7.2 Discourse versions prior to 2026.8.0 Description The post sanitizer allows a stored cross-origin iframe to bypass the allowed iframe...