CVE-2026-116802

DOMPurify before 3.4.17 XSS via SMIL attributeName Guard Bypass in XHTML Mode

At a glance

Severity: MEDIUM 5.1
EPSS: EPSS 0.22 % · percentile 12 (2026-10-27)
State: PUBLISHED
Published: 2026-10-26
Updated: 2026-10-26
Assigner: VulnCheck
NVD status: Awaiting Analysis

Description

DOMPurify before 3.4.17 contains a cross-site scripting vulnerability that allows attackers to bypass the SMIL attributeName=href guard when PARSER_MEDIA_TYPE is application/xhtml+xml, because transformCaseFunc does not lowercase attribute names. Attackers can submit SVG with an animate or set element using attributeName="href" and a javascript: entry in values to execute script when users click the sanitized link.

Scores

Version	Score	Vector	Scored by
CVSS 4.0	MEDIUM 5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N	VulnCheck
CVSS 3.1	MEDIUM 6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N	VulnCheck
CVSS 4.0	MEDIUM 5.1	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD · disclosure@vulncheck.com (Secondary)
CVSS 3.1	MEDIUM 6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N	NVD · disclosure@vulncheck.com (Primary)

Weaknesses (CWE)

CWE-79

Advisories

GHSA-c6gr-qvv4-5v3f — DOMPurify: SMIL attributeName=href guard is skipped when PARSER_MEDIA_TYPE is application/xhtml+xml

European references

ENISA EUVD · EUVD-2026-110510
GCVE · GCVE-0-2026-116802

Affected products

Product	Versions
cure53 · DOMPurify	affected 0 < 3.4.17 ; unaffected 3.4.17

References

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD