CVE-2026-91132

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowediframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched...

CVE-2026-91123

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...

EUVD-2026-86303

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowediframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched...

CVE-2026-91132 Discourse: Wildcard iframe origin allowlist bypass via authority separators

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowediframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched...

CVE-2026-91132 Discourse: Wildcard iframe origin allowlist bypass via authority separators

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowediframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched...

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-2026-91134 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-2026-91123: Improper Limitation of a Pathname to a Restricted Directory

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-2026-91132: Origin Validation Error

Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowediframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched...

CVE-2025-48877

Discourse is an open-source discussion platform. Prior to version 3.4.4 of the stable branch, version 3.5.0.beta5 of the beta branch, and version 3.5.0.beta6-dev of the tests-passed branch, Codepen is present in the default allowediframes site setting, and it can potentially auto-run arbitrary JS...

CVE-2025-48877: Insecure Automated Optimizations

Discourse is an open-source discussion platform. Prior to version 3.4.4 of the stable branch, version 3.5.0.beta5 of the beta branch, and version 3.5.0.beta6-dev of the tests-passed branch, Codepen is present in the default allowediframes site setting, and it can potentially auto-run arbitrary JS...

CVE-2024-39320: Improper Neutralization of Special Elements in Output Used by a Downstream Component

Discourse is an open source discussion platform. Prior to 3.2.5 and 3.3.0.beta5, the vulnerability allows an attacker to inject iframes from any domain, bypassing the intended restrictions enforced by the allowediframes setting. This vulnerability is fixed in 3.2.5 and 3.3.0.beta5...