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.
CVE-2026-91119
MEDIUMPre-NVD 6.46.4
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: secondary
6.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 6.4Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.4
- EG Score
- 6.4(low)
- EG Risk
- 33(Track)EG Risk 33/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity64% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
September 24, 2026
Last Modified
September 24, 2026
Advisory Details (6)
Auto-updated Sep 24, 2026Patch available. Sources: github, github_pr, github_commit.
github_commit
commit c4748f651d9d (discourse/discourse)
Fix landed in discourse/discourse commit c4748f651d9d — awaiting tagged release
https://github.com/discourse/discourse/commit/c4748f651d9d2f3a6dd3106a4d5564536c645168github_commit
commit 77a81c7a3a7f (discourse/discourse)
Fix landed in discourse/discourse commit 77a81c7a3a7f — awaiting tagged release
https://github.com/discourse/discourse/commit/77a81c7a3a7ff9e94b355e32b8f379f2d389e05agithub_commit
commit 66653c484cfb (discourse/discourse)
Fix landed in discourse/discourse commit 66653c484cfb — awaiting tagged release
https://github.com/discourse/discourse/commit/66653c484cfb91bc346f9a326f6945387f17b035github_commit
commit 20dbf112760e (discourse/discourse)
Fix landed in discourse/discourse commit 20dbf112760e — awaiting tagged release
https://github.com/discourse/discourse/commit/20dbf112760eb1d6a58f2e49aeef7546898b6f1cgithub_pr
Security fixes for main
Fix merged in discourse/discourse PR #42882 on 2026-08-25 — awaiting tagged release
https://github.com/discourse/discourse/pull/42882github Patch Available
Encode action_code_who in mention URLs · Advisory · discourse/discourse · GitHub
https://github.com/discourse/discourse/security/advisories/GHSA-pv3p-p3m9-v8v3Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 3× in last 7d / 3× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-09-24 18:35 UTCEG score recompute
- 2026-09-24 17:18 UTCEG score recompute
- 2026-09-24 17:17 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(4)
What is CVE-2026-91119?
CVE-2026-91119 is a medium vulnerability published on September 24, 2026. 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 actioncodewho value into mention-link href attributes without URL encoding. A quote-bearing display name could…
When was CVE-2026-91119 disclosed?
CVE-2026-91119 was first published in the National Vulnerability Database on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-91119?
CVE-2026-91119 has a CVSS v3 base score of 6.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-91119?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91119, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-91119
Is Your Infrastructure Affected by CVE-2026-91119?
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