Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1000 CNY

100.0%
Buy Us a Coffee

CVE-2026-27166— Discourse vulnerable to HTML injection via prohibited iframe URLs

CVSS 4.1 · Medium EPSS 0.03% · P10
Get alerts for future matching vulnerabilitiesLog in to subscribe

I. Basic Information for CVE-2026-27166

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Discourse vulnerable to HTML injection via prohibited iframe URLs
Source: NVD (National Vulnerability Database)
Vulnerability Description
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.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
Web页面中脚本相关HTML标签转义处理不恰当(基本跨站脚本)
Source: NVD (National Vulnerability Database)
Vulnerability Title
Discourse 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Discourse是Discourse开源的一套开源的社区讨论平台。该平台包括社区、电子邮件和聊天室等功能。 Discourse 2026.3.0-latest.1之前版本、2026.2.1之前版本和2026.1.2之前版本存在安全漏洞，该漏洞源于默认Codepen允许的iframe值清理不足，可能导致攻击者诱骗用户更改主页URL。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
discoursediscourse < 2026.3.0-latest.1 -

II. Public POCs for CVE-2026-27166

#POC DescriptionSource LinkShenlong Link
AI-Generated POCPremium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-27166

请登录查看更多情报信息。

Same Patch Batch · discourse · 2026-03-19 · 17 CVEs total

CVE-2026-333556.5 MEDIUMDiscourse filters whisper posts from private-posts feed
CVE-2026-334105.4 MEDIUMDiscourse hardens chat DM channel creation and expansion
CVE-2026-274545.3 MEDIUMDiscourse has check revision visibility on posts endpoint
CVE-2026-333954.4 MEDIUMDiscourse has stored click‑based XSS via Graphviz SVG javascript: links
CVE-2026-320994.3 MEDIUMDiscourse prevents hidden profile data leak via user onebox
CVE-2026-333934.3 MEDIUMDiscourse fixes loose hostname matching in spam host allowlist
CVE-2026-333942.7 LOWDiscourse leaks PM post edits to moderators
CVE-2026-334082.2 LOWDiscourse has Improper Authorization in "Post Edits" Report For Moderators
CVE-2026-27491Discourse has a bypass of official warnings messages by non-staff users
CVE-2026-27570Discourse Vulnerable to Stored XSS via Shared AI Conversation Onebox
CVE-2026-27740Discourse has Stored XSS in AI Triage Automation
CVE-2026-27934Discourse leaks private topic title and post excerpt via user action API endpoint
CVE-2026-27935Discourse leaks private topic metadata to non-authorized users
CVE-2026-27936Discourse discloses restricted post-action counts to non-privileged users
CVE-2026-29072Discourse missing permission check for policy creation in discourse-policy
CVE-2026-28282Discourse vulnerable to group membership addition permission bypass via discourse-policy p

IV. Related Vulnerabilities

Same product: discourse
Same vendor: discourse
Same weakness: CWE-80

V. Comments for CVE-2026-27166

No comments yet

Leave a comment