EUVD-2026-86325Published

xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-61784

Published

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.

Source published: 24 Sep 2026 17:35:57 UTC
Source modified: 24 Sep 2026 18:03:05 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

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CVSS 3.1 · 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

euvd · EUVD-2026-86325

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Sep 24, 2026, 5:35:57 PM

dateUpdated: Sep 24, 2026, 6:03:05 PM

Source published: Sep 24, 2026, 5:35:57 PM (timezone not stated)
Source modified: Sep 24, 2026, 6:03:05 PM (timezone not stated)
Observed here: 11 Nov 2026 15:03:08 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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EUVD CVSS 3.1 · 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

nvd · CVE-2026-61784

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Deferred

Weakness classifications: CWE-79 · CWE-116

Original publisher date fields

published: 2026-09-24T18:17:16.640

lastModified: 2026-09-30T17:32:07.107

Source published: 24 Sep 2026 18:17:16 UTC
Source modified: 30 Sep 2026 17:32:07 UTC
Observed here: 25 Oct 2026 14:19:28 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

osv · GHSA-j8r4-32c5-33rc

Published

xhtml-purifier does 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 HTML-entity-encodes attribute values before serialization.

Source published: 24 Sep 2026 19:33:23 UTC
Source modified: 24 Sep 2026 19:45:04 UTC
Observed here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Publisher rating · MODERATE