CVE-2026-91119 json
Discourse: Encode action_code_who in mention URLs
published 2026-09-24 46 d ago modified 2026-10-01 39 d ago also BIT-discourse-2026-91119 , EUVD-2026-86307 , GHSA-pv3p-p3m9-v8v3
- cvss
- 6.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 10%
- public exploits
- 0
- none known
Summary
Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the topic small-action and nested-activity-log components interpolated the free-form action_code_who value into mention-link href attributes without URL encoding. A quote-bearing display name could terminate the intended URL attribute and inject attacker-controlled elements into the trusted rendered markup. Although the visible mention text was escaped, the unencoded path component allowed stored HTML injection when another user viewed the affected topic action or activity log. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.
Patch / fix
- bitnami discourse 2026.8.0
- discourse discourse 2026.1.8, 2026.6.3, 2026.7.2, 2026.8.0
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 42 d ago
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| OSV | 3.1 | 6.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | discourse | <2026.8.0 |
2026.8.0 |
Affected products
- discourse discourse
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/discourse/discourse/pull/42882
web
-
github.com
/discourse/discourse/commit/20dbf112760eb1d6a58f2e49aeef7546898b6f1c
web
-
github.com
/discourse/discourse/commit/66653c484cfb91bc346f9a326f6945387f17b035
web
-
github.com
/discourse/discourse/commit/77a81c7a3a7ff9e94b355e32b8f379f2d389e05a
web
-
github.com
/discourse/discourse/commit/c4748f651d9d2f3a6dd3106a4d5564536c645168
web
-
github.com
/discourse/discourse/security/advisories/GHSA-pv3p-p3m9-v8v3
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-91119
web
Sources
- CVE List CVE-2026-91119
- NVD CVE-2026-91119
- OSV BIT-discourse-2026-91119
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.