XSS in Discourse
CVE-2025-48954
Discourse is an open-source discussion platform. Versions prior to 3.5.0.beta6 are vulnerable to cross-site scripting when the content security policy isn't enabled when using social logins. Version 3.5.0.beta6 patches the issue. As a workaround, have the content security policy enabled.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.006 (46.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.
Affected products
- Discourse — versions < 3.5.0.beta6, 3.5.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-48954?
- CVE-2025-48954 is a high-severity vulnerability in Discourse, classified under Cross-site Scripting. CVSS score: 8.1/10. Published 2025-06-25.
- How severe is CVE-2025-48954?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2025-48954 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.