CVE-2026-55424 json
Discourse: Topic featured link susceptible to stored XSS
published 2026-07-09 4 mo ago modified 2026-09-08 2 mo ago also BIT-discourse-2026-55424 , EUVD-2026-42733 , GHSA-695w-7fv8-mxg3
- cvss
- 5.4
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 36%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- bitnami discourse 2026.1.5, 2026.4.2, 2026.5.1
- discourse discourse 2026.1.5, 2026.4.2, 2026.5.1
- github.com/discourse/discourse@1bce888 commit
- github.com/discourse/discourse@6679d9a commit
- github.com/discourse/discourse@6828aee commit
- github.com/discourse/discourse@c9b9405 commit
- github.com/discourse/discourse/releases/tag/v2026.1.5 release
- github.com/discourse/discourse/releases/tag/v2026.4.2 release
- github.com/discourse/discourse/releases/tag/v2026.5.1 release
- github.com/discourse/discourse/releases/tag/v2026.6.0 release
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 4 mo ago
Exploit prediction
0.41% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.4 | 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 |
| CNA | 4.0 | 7.4 | 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 |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | discourse | >=2026.1.0, <2026.1.5 >=2026.4.0, <2026.4.2 >=2026.5.0, <2026.5.1 |
2026.1.5 2026.4.2 2026.5.1 |
Affected products
- discourse discourse
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/discourse/discourse/commit/1bce8881e4253d9bbab56f011a12ef899b926b59
patch
-
github.com
/discourse/discourse/commit/6679d9a5083488bae10c2adbb345c481c583242c
patch
-
github.com
/discourse/discourse/commit/6828aee9b15c2655d63b515ac919830bd540ff83
patch
-
github.com
/discourse/discourse/commit/c9b9405f5bd0bf0269e505e28e3aad388d7657c5
patch
-
github.com
/discourse/discourse/security/advisories/GHSA-695w-7fv8-mxg3
vendor-advisory, advisory
-
github.com
/discourse/discourse/releases/tag/v2026.1.5
release-notes, article
-
github.com
/discourse/discourse/releases/tag/v2026.4.2
release-notes, article
-
github.com
/discourse/discourse/releases/tag/v2026.5.1
release-notes, article
-
github.com
/discourse/discourse/releases/tag/v2026.6.0
release-notes, article
-
nvd.nist.gov
/vuln/detail/CVE-2026-55424
web
Sources
- CVE List CVE-2026-55424
- NVD CVE-2026-55424
- OSV BIT-discourse-2026-55424
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.