Dashboard / CVE-2017-20290

CVE-2017-20290

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 60/100
Published: 2026-10-22 Modified: 2026-10-22 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Active
S: X
AT: None
VC: None
VI: None
VA: None

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 Classification (1)

References & Advisories (4)

Bug Bounty Relevance

60 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

5.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.27%
Raw Score 0.002650
Percentile 18.4%
Date 2026-10-29

Intelligence Sources

nvd ref →

External Links