CVE-2026-59830

MEDIUMPre-NVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 81% of all CVEs by exploit prediction. 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: epss, secondary
Trending — 3 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Discourse is an open-source discussion platform. Prior to 2026.7.0, the post action component failed to escape user-controlled display names before interpolating them into an HTML string passed to trustHTML. A user who could choose a crafted display name could persist markup in post action descriptions. Viewing the affected user activity streams could execute attacker-controlled script in another user's browser. This issue is fixed in version 2026.7.0.

CVSS v3
5.4
EG Score
5.4(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: 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 computed
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

September 21, 2026

Last Modified

September 23, 2026

Advisory Details (2)

Auto-updated Sep 21, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Stored XSS via unescaped actor name in post actions · Advisory · discourse/discourse · GitHub

https://github.com/discourse/discourse/security/advisories/GHSA-x6mf-p7cg-69rw
github_commit

commit dd786594ddd0 (discourse/discourse)

Fix landed in discourse/discourse commit dd786594ddd0 — awaiting tagged release

https://github.com/discourse/discourse/commit/dd786594ddd088657a7e6f9fefba5bd889965fe4

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× 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.

  1. 2026-09-24 16:15 UTCEG score recompute
  2. 2026-09-24 14:04 UTCEPSS rescore
  3. 2026-09-23 17:54 UTCEPSS rescore
  4. 2026-09-22 16:22 UTCEG score recompute
  5. 2026-09-22 15:45 UTCEG score recompute
  6. 2026-09-21 22:27 UTCEG score recompute
  7. 2026-09-21 21:27 UTCEG score recompute
  8. 2026-09-21 21:26 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-59830?
CVE-2026-59830 is a medium vulnerability published on September 21, 2026. Discourse is an open-source discussion platform. Prior to 2026.7.0, the post action component failed to escape user-controlled display names before interpolating them into an HTML string passed to trustHTML. A user who could choose a crafted display name could persist markup in post action…
When was CVE-2026-59830 disclosed?
CVE-2026-59830 was first published in the National Vulnerability Database on September 21, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59830 actively exploited?
CVE-2026-59830 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.0% of all scored CVEs.
What is the CVSS score of CVE-2026-59830?
CVE-2026-59830 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-59830?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59830, 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-2026-59830

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