CVE-2026-27570
Discourse Vulnerable to Stored XSS via Shared AI Conversation Onebox
Description
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, tighten access by changing the `ai_bot_public_sharing_allowed_groups` site setting.
INFO
Published Date :
March 19, 2026, 9:17 p.m.
Last Modified :
March 25, 2026, 12:59 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Discourse to a patched version.
- Configure ai_bot_public_sharing_allowed_groups site setting.
- Restrict access by tightening site settings.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-27570.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-27570 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-27570
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-27570 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-27570 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 25, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Added CPE Configuration OR *cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* versions from (including) 2026.1.0 up to (excluding) 2026.1.2 *cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* versions from (including) 2026.2.0 up to (excluding) 2026.2.1 *cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:* Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/43a5a60b595f0120e6adfc131f2408508fe341f1 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/c14f8f52b7999328bd9f8665f2ecfa24dadc4bf1 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/commit/f2aafa5c7467c94fcd4ebd36785a98e77ca088cc Types: Patch Added Reference Type GitHub, Inc.: https://github.com/discourse/discourse/security/advisories/GHSA-hfxw-89hw-vwmv Types: Vendor Advisory -
New CVE Received by [email protected]
Mar. 19, 2026
Action Type Old Value New Value Added Description Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, tighten access by changing the `ai_bot_public_sharing_allowed_groups` site setting. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-79 Added Reference https://github.com/discourse/discourse/commit/43a5a60b595f0120e6adfc131f2408508fe341f1 Added Reference https://github.com/discourse/discourse/commit/c14f8f52b7999328bd9f8665f2ecfa24dadc4bf1 Added Reference https://github.com/discourse/discourse/commit/f2aafa5c7467c94fcd4ebd36785a98e77ca088cc Added Reference https://github.com/discourse/discourse/security/advisories/GHSA-hfxw-89hw-vwmv