CVE-2026-91120

MEDIUMPre-NVD 5.45.4
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 5.4 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
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: —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 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, provider-controlled video titles in lazy video embeds could be reparsed as HTML when Discourse generated notification emails or chat summaries. A user with standard posting privileges could create a post for an enabled YouTube, Vimeo, or TikTok provider whose title contained markup, and the email and chat-summary rendering path would place that markup into the output instead of treating it solely as text. Recipients using HTML-capable email clients could see injected content, potentially including event handlers, but the issue did not directly expose a Discourse browser session or affect the forum page itself. Lazy video embeds must be enabled, which is the default configuration. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.

CVSS v3
5.4
EG Score
5.4(low)
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
—
EPSS %ILE
—
KEV
Not listed

Published

September 24, 2026

Last Modified

September 24, 2026

Advisory Details (6)

Auto-updated Sep 24, 2026
Patch available. Sources: github, github_pr, github_commit.
github_commit

commit ed8b47df80bc (discourse/discourse)

Fix landed in discourse/discourse commit ed8b47df80bc — awaiting tagged release

https://github.com/discourse/discourse/commit/ed8b47df80bcc9f0bd70773fc399c9386f9d52dd
github_commit

commit e7de8285203a (discourse/discourse)

Fix landed in discourse/discourse commit e7de8285203a — awaiting tagged release

https://github.com/discourse/discourse/commit/e7de8285203a2edf85beff3b951e66aeb7e5dc76
github_commit

commit 8338919df4ec (discourse/discourse)

Fix landed in discourse/discourse commit 8338919df4ec — awaiting tagged release

https://github.com/discourse/discourse/commit/8338919df4ecbd0fb85314b762772cc033b764e3
github_commit

commit 6bf1cdcb3ae1 (discourse/discourse)

Fix landed in discourse/discourse commit 6bf1cdcb3ae1 — awaiting tagged release

https://github.com/discourse/discourse/commit/6bf1cdcb3ae1aa146e1fd953a62046bf4a1f143f
github_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/42882
github Patch Available

Stored HTML injection in video notification emails · Advisory · discourse/discourse · GitHub

https://github.com/discourse/discourse/security/advisories/GHSA-h7cg-2vww-m45c

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 4× 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 18:35 UTCEG score recompute
  2. 2026-09-24 17:32 UTCEG score recompute
  3. 2026-09-24 17:18 UTCEG score recompute
  4. 2026-09-24 17:17 UTCMITRE cvelistV5first tracked

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Frequently asked(4)

What is CVE-2026-91120?
CVE-2026-91120 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, provider-controlled video titles in lazy video embeds could be reparsed as HTML when Discourse generated notification emails or chat summaries. A user with standard posting privileges could create…
When was CVE-2026-91120 disclosed?
CVE-2026-91120 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-2026-91120?
CVE-2026-91120 has a CVSS v3 base score of 5.4 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-91120?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-91120, 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

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