CVE-2023-25172

Discourse vulnerable to Cross-site Scripting - user name displayed on post

MEDIUM
5.4
CVSS Score
Published: March 17, 2023 at 04:07 PM UTC
Updated: June 17, 2026 at 05:40 AM UTC
1 product affected across 1 vendorDiscourse

Using discourse by discourse?

Get instant alerts when new vulnerabilities affect discourse - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM5.4
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

Discourse is an open-source discussion platform. Prior to version 3.0.1 of the `stable` branch and version 3.1.0.beta2 of the `beta` and `tests-passed` branches, a maliciously crafted URL can be included in a user's full name field to to carry out cross-site scripting attacks on sites with a disabled or overly permissive CSP (Content Security Policy). Discourse's default CSP prevents this vulnerability. The vulnerability is patched in version 3.0.1 of the `stable` branch and version 3.1.0.beta2 of the `beta` and `tests-passed` branches. As a workaround, enable and/or restore your site's CSP to the default one provided with Discourse.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.0.1v < 3.1.0v < 3.1.0.beta23.1.0 beta1
Affected range stops below 3.0.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.1.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.1.0.beta2, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card