CVE-2026-84371

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: 0.2%, top 92% 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
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.

ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that attributeName selecting href or xlink:href gives the sibling values, from, to, or by attribute SVG SMIL URL semantics. In configurations that allow the animate, animateColor, animateMotion, animateTransform, or set elements, a values list can begin with a safe fragment and contain a later executable destination that survives allowedSchemesAppliedToAttributes checking. When the sanitized SVG is rendered, the browser can copy that later destination into the live link, and a victim who activates the link can execute script in the application's origin. This issue is fixed in version 2.17.7.

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
8%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 9, 2026

Advisory Details (5)

Auto-updated Sep 1, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit.
generic

apostrophe/packages/sanitize-html/CHANGELOG.md at main · apostrophecms/apostrophe · GitHub

https://github.com/apostrophecms/apostrophe/blob/main/packages/sanitize-html/CHANGELOG.md
github_commit

commit 38ff1106c817 (apostrophecms/apostrophe)

Fix landed in apostrophecms/apostrophe commit 38ff1106c817 — awaiting tagged release

https://github.com/apostrophecms/apostrophe/commit/38ff1106c8176b16c2da9872acd9b449adcbb949
github_commit

commit 1135516a1a4a (apostrophecms/apostrophe)

Fix landed in apostrophecms/apostrophe commit 1135516a1a4a — awaiting tagged release

https://github.com/apostrophecms/apostrophe/commit/1135516a1a4a8f9638641c460488a43d8af20081
github_pr

Stable reconciliation q2 m3 2026

Fix merged in apostrophecms/apostrophe PR #5552 on 2026-08-12 — awaiting tagged release

https://github.com/apostrophecms/apostrophe/pull/5552
github Patch Available🟡 PoC Available

Stored XSS via SVG SMIL URI-list scheme-policy bypass · Advisory · apostrophecms/apostrophe · GitHub

https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-g8qq-57p8-ggw5

Vendor Advisories for CVE-2026-84371(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
sanitize-html—2.17.7—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 29× 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. 2026-09-19 05:31 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 04:38 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-17 03:45 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-16 02:52 UTCEG score recompute
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-14 01:04 UTCEG score recompute
  12. 2026-09-13 00:10 UTCEG score recompute
  13. 2026-09-11 23:17 UTCEG score recompute
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-10 22:04 UTCEG score recompute
  17. 2026-09-07 20:52 UTCEG score recompute
  18. 2026-09-06 19:59 UTCEG score recompute
  19. 2026-09-06 13:48 UTCEPSS rescore
  20. 2026-09-05 19:05 UTCEG score recompute
  21. 2026-09-05 15:31 UTCEPSS rescore
  22. 2026-09-04 18:11 UTCEG score recompute
  23. 2026-09-04 05:07 UTCEPSS rescore
  24. 2026-09-03 17:16 UTCEG score recompute
  25. 2026-09-02 16:20 UTCEG score recompute
Show 4 more
  1. 2026-09-02 14:12 UTCEPSS rescore
  2. 2026-09-01 21:26 UTCEG score recompute
  3. 2026-09-01 20:53 UTCEG score recompute
  4. 2026-09-01 20:52 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-84371?
CVE-2026-84371 is a medium vulnerability published on September 1, 2026. ApostropheCMS is an open-source Node.js content management system, and sanitize-html provides a simple HTML sanitizer with a clear API. From version 1.9.0 until version 2.17.7, packages/sanitize-html/index.js validates an animation value attribute as one flat URL and does not recognize that…
When was CVE-2026-84371 disclosed?
CVE-2026-84371 was first published in the National Vulnerability Database on September 1, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84371 actively exploited?
CVE-2026-84371 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 91.6% of all scored CVEs.
What is the CVSS score of CVE-2026-84371?
CVE-2026-84371 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-84371?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84371, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-84371

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