DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.7, DOMPurify IN_PLACE sanitization could skip shadow contents attached to an element inside .content, allowing attacker-controlled markup such as event handlers, JavaScript URLs, or scripts to survive and execute when an application cloned and inserted the sanitized template. This issue is fixed in version 3.4.7.
CVE-2026-49978
MEDIUMNVD 6.16.3▲Elevated
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 69% 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
6.1
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.3(medium)
- EPSS
- 21.3%
- KEV
- Not listed
Published
June 15, 2026
Last Modified
July 21, 2026
Advisory Details (2)
Auto-updated Jul 15, 2026🔬 Proof of concept available. Patch available. Sources: github_release, github.
github Patch Available🟡 PoC Available
DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside <template>.content · Advisory · cure53/DOMPurify · GitHub
https://github.com/cure53/DOMPurify/security/advisories/GHSA-rp9w-3fw7-7cwqgithub_release Patch Available
DOMPurify 3.4.7
Patch available: cure53/DOMPurify 3.4.7
https://github.com/cure53/DOMPurify/releases/tag/3.4.7Vendor Advisories for CVE-2026-49978(2)
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)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| dompurify | — | 3.4.7 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 13× 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.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 21:19 UTCNVD updateCVSS v3 → 6.1
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-14 20:33 UTCEG score recompute▲ 6.30
- 2026-07-14 20:30 UTCMITRE cvelistV5CVSS v3 → 6.3 · CVSS v4 → 6.3
- 2026-06-15 20:12 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-49978?
CVE-2026-49978 is a medium vulnerability published on June 15, 2026. DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.7, DOMPurify IN_PLACE sanitization could skip shadow contents attached to an element inside <template>.content, allowing attacker-controlled markup such as event handlers, JavaScript URLs, or scripts to…
When was CVE-2026-49978 disclosed?
CVE-2026-49978 was first published in the National Vulnerability Database on June 15, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49978 actively exploited?
CVE-2026-49978 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 21.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-49978?
CVE-2026-49978 has a CVSS v3 base score of 6.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.3.
How do I remediate CVE-2026-49978?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49978, 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-2026-49978
Is Your Infrastructure Affected by CVE-2026-49978?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.