Medium severity · published Feb 26, 2026
CVE-2026-27154
Discourse has XSS when editing a malicious post
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, a user full name can be evaluated as raw HTML when the following settings are set: `display_name_on_posts` => true; and `prioritize_username_in_ux` => false. Editing a post of a malicious user would trigger an XSS. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DI
discourse · discourse
< 2025.12.2; >= 2026.1.0-latest, < 2026.1.1; >= 2026.2.0-latest, < 2026.2.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27154
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27154
Vendor Advisory
https://github.com/discourse/discourse/security/advisories/GHSA-xv43-5gcp-wgw8
More from discourse
9.9
CVE-2025-68662
FinalDestination hostname matching allows SSRF protection bypass
9.8
CVE-2025-53102
Discourse's WebAuthn challenge isn't cleared from user session after authentication
9.8
CVE-2025-48877
Discourse vulnerable to auto-executing of third-party code in embedded CodePen iframe
9.8
CVE-2023-47121
Discourse is an open source platform for community discussion
9.8
CVE-2021-41163
Discourse is an open source platform for community discussion