CVE-2026-8630: medium-severity vulnerability in EmilStenstrom justhtml
justhtml before 1.12.0 Mutation XSS via Raw Text Elements
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.1epss 0.3%
justhtml before 1.12.0 (versions <= 1.11.0) contains a mutation cross-site scripting (mXSS) vulnerability in the serialization of raw-text elements such as <style> and <script>. When a DOM tree is processed by sanitize_dom() using a custom policy that keeps these elements, text nodes inside them are serialized literally without escaping, allowing attacker-controlled text containing the matching closing tag sequence to break out of the raw-text context and inject arbitrary HTML into the serialized output. The default sanitization policy is not affected because it drops the contents of style and script.
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
Affected products
EmilStenstrom · justhtmlRelated CVEs — EmilStenstrom justhtml
In the same product, most dangerous first.
CVE-2026-4671HIGHjusthtml before 1.18.0 Denial of Service via CSS SelectorEPSS 0.7%CVE-2026-8445CRITICALjusthtml before 1.12.0 Sanitizer Bypass via MarkdownEPSS 0.6%CVE-2026-7808CRITICALjusthtml before 1.16.0 Multiple Security Issues via SanitizationEPSS 0.6%CVE-2026-5388CRITICALjusthtml before 1.15.0 Multiple Security IssuesEPSS 0.6%CVE-2026-9769HIGHjusthtml before 1.10.0 Denial of Service via deeply nested HTMLEPSS 0.3%CVE-2026-77088MEDIUMjusthtml 0.9.0 through 1.21.0 Cross-Site Scripting via code-spanEPSS 0.3%