CVE-2026-33395 Discourse — Exploit & Vulnerability Details MEDIUM

Parameter	Value
CVSS	5.4 (MEDIUM)
Affected Versions	2026.1.0 — 2026.2.1
Fixed In	2026.1.2
Type	CWE-79 (Cross-Site Scripting (XSS))
Vendor	Discourse
Public PoC	No

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the discourse-graphviz plugin contains a stored cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious JavaScript code through DOT graph definitions. For instances with CSP disabled only.

Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable the graphviz plugin, upgrade to a patched version, or enable a content security policy.

Attack Parameters

Attack Vector

Network

Can be exploited remotely

Attack Complexity

Low

Easy to exploit

Privileges Required

Low

Basic privileges needed

User Interaction

Required

User action required

Impact Assessment

Confidentiality

Low

Partial data leak

Integrity

Low

Partial data modification

Availability

None

No disruption

CVSS Vector v3.1

Weakness Type (CWE)

CWE-79 Cross-Site Scripting (XSS)

Vulnerable Products 3

Configuration	From (including)	Up to (excluding)
Discourse Discourse cpe:2.3:a:discourse:discourse::::::::	`2026.1.0`	`2026.1.2`
Discourse Discourse cpe:2.3:a:discourse:discourse::::::::	`2026.2.0`	`2026.2.1`
Discourse Discourse cpe:2.3:a:discourse:discourse:2026.3.0::::latest:::	—	—