CVE-2026-55424

HIGH

Discourse: Topic featured link susceptible to stored XSS

Title source: cna
STIX 2.1

Description

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, a topic "featured link" was not sufficiently normalized and escaped before being rendered in the topic list, allowing a user who can set a featured link to inject JavaScript when default Content Security Policy protections were modified or disabled. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

References (9)

Core 9
Core References

Scores

CVSS v4 7.4
EPSS 0.0047
EPSS Percentile 37.4%
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/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

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-79
Status published
Products (3)
discourse/discourse >= 2026.1.0-latest, < 2026.1.5
discourse/discourse >= 2026.4.0-latest, < 2026.4.2
discourse/discourse >= 2026.5.0-latest, < 2026.5.1
Published Jul 09, 2026
Tracked Since Jul 10, 2026