5.4

CVE-2026-27166

Discourse vulnerable to HTML injection via prohibited iframe URLs

Discourse is an open source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1 and  2026.1.2, insufficient cleanup in the default Codepen allowed iframes value allows an attacker to trick a user into changing the URL of the main page. This issue has been fixed in versions 2026.3.0-latest.1, 2026.2.1 and  2026.1.2. To workaround this issue, remove Codepen from the list of allowed iframes.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Discourse ≫ Discourse Version < 2026.3.0
Discourse ≫ Discourse Version >= 2026.1.0 < 2026.1.2
Discourse ≫ Discourse Version >= 2026.2.0 < 2026.2.1
Discourse ≫ Discourse Version2026.3.0 SwEditionlatest
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.19% 0.083
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 5.4 2.3 2.7
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
security-advisories@github.com 4.1 2.3 1.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N
CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages.

https://github.com/discourse/discourse/security/advisories/GHSA-h653-cq78-vjj2
Vendor Advisory
https://github.com/discourse/discourse/commit/c4762a4fac2f61f52f325396b11d3aeb955ea925
Patch