CVE & CISA-KEV Catalog

CVE-2026-61784

MEDIUM
6.1
CVSS v3
NVD

Description

xhtml-purifier is a Node.js library to take in raw/unknown/untrusted HTML and output cleaned, purified, trusted HTML. Versions prior to 0.4.3 do not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix in version 0.4.3 HTML-entity-encodes attribute values before serialization.

How to fix

Remediation Available
xhtml-purifiernpm
Fixed in:0.4.3GHSA-j8r4-32c5-33rc

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged

Impact

ConfidentialityLow
IntegrityLow
AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Exploit Intelligence

0.17%probability of exploitation in 30 days
6thpercentile

Low risk: more likely to be exploited than 6% of all known CVEs.

References

Other references2

Related Vulnerabilities

Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2018-12998Medium6.199%--
CVE-2020-11022Medium6.999%-Fix
CVE-2019-3929Critical9.899%KEVFix
CVE-2020-9496Medium6.199%--
CVE-2023-28341Medium6.199%-Fix
CVE-2021-25299Medium6.198%--

Common questions

How do I fix CVE-2026-61784?

Upgrade xhtml-purifier to 0.4.3 or later.

Is CVE-2026-61784 being actively exploited?

Not that we know of. CVE-2026-61784 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.17% is the estimated probability that it will be exploited in the next 30 days. That is higher than 6% of all scored CVEs.

How severe is CVE-2026-61784?

CVE-2026-61784 has a CVSS v3 base score of 6.1, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-61784 affect?

Published advisories record a fix for xhtml-purifier (npm). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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CVE-2026-61784 severity badge

Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-30.