CVE-2026-116538: mganss HtmlSanitizer

HtmlSanitizer before 9.2.1039 XSS via SanitizeDom Body and HTML Attributes

CVSS 2.3 LowEPSS 0.0029 · 21st percentile

Published by the CVE Program (CNA: VulnCheck) at 26 Oct 2026, 14:59 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

Affected products, as the CNA wrote them
Vendor	Product	Versions
mganss	HtmlSanitizer Package name: HtmlSanitizer https://www.nuget.org/packages/HtmlSanitizer pkg:nuget/HtmlSanitizer	affected before 9.2.1039 semver affected 10.0.0-beta to before 10.0.1037-beta semver Other versions: unaffected

Identifiers

CVE-2026-116538

CNA

VulnCheck

Weakness (CWE)

CWE-79

Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
2.3	Low	4.0	CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N	CNA (VulnCheck)Used for this record
4.7	Medium	3.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0029, the 21st percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

26 Oct 2026, 14:59 UTC Confirmed by the CVE List

Sources

References from the CNA

github.com/mganss/HtmlSanitizer/commit/96afbc818e64de7571ea17954a05d523e819c56f patch
github.com/mganss/HtmlSanitizer/commit/ab626e7a4f2893f7e9ec0a72779ae19c5ec439a7 patch
github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L456-L465 technical-description
github.com/mganss/HtmlSanitizer/blob/v9.2.995/src/HtmlSanitizer/HtmlSanitizer.cs#L555-L583 technical-description
joshua.hu/htmlsanitizer-sanitizedom-body-html-attribute-bypass technical-description
github.com/mganss/HtmlSanitizer/releases/tag/v9.2.1039 release-notes
github.com/mganss/HtmlSanitizer/releases/tag/v10.0.1037-beta release-notes
github.com/mganss/HtmlSanitizer product
www.vulncheck.com/advisories/htmlsanitizer-before-9.2.1039-xss-via-sanitizedom-body-and-html-attributes third-party-advisory

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.