CVE-2017-20290 Discourse < 1.9.0.beta13 Reflected XSS via /email/unsubscribed
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2017-20290?
CVE-2017-20290 is a medium-severity vulnerability in Discourse, published on 22 Oct 2026.
Official description
Discourse 1.9.0.beta2 before 1.9.0.beta13 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject scripts through the email parameter of /email/unsubscribed. Attackers can craft GET requests with SVG onload payloads, which unsubscribed.html.erb renders unescaped via html_safe, executing JavaScript in victims' browsers. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-19.
Weakness: CWE-79
Which versions are affected by CVE-2017-20290?
How do I fix CVE-2017-20290?
No fix has been published for CVE-2017-20290 yet. Limit exposure of the affected software until one is available.
Is CVE-2017-20290 being exploited?
There is no known exploitation of CVE-2017-20290 in the wild and no public exploit code.
Sources
Also known as GHSA-9225-76qg-xfwx.