Cross-site scripting via unsanitized selectedcontent clones
Published Aug 23, 2026 · Updated Aug 23, 2026
Cross-site scripting in JustHTML before 3.11.0 allows remote attackers to inject executable browser content through crafted HTML. In the default fused parser, _project_selectedcontent deep-clones SVG or MathML children after deferred drop and unwrap lists are built, so the clones retain event-handler attributes and bypass later sanitization. An application must sanitize attacker-controlled HTML and place the serialized result in a browser; the resulting script runs with that application's content origin.
Summary
What happened
Cross-site scripting in JustHTML before 3.11.0 allows remote attackers to inject executable browser content through crafted HTML. In the default fused parser, _project_selectedcontent deep-clones SVG or MathML children after deferred drop and unwrap lists are built, so the clones retain event-handler attributes and bypass later sanitization. An application must sanitize attacker-controlled HTML and place the serialized result in a browser; the resulting script runs with that application's content origin.
The record
- CVE
- CVE-2026-74793
- Published
- Aug 23, 2026
- Updated
- Aug 23, 2026
- Vendor
- Emil Stenström
- Product
- JustHTML
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 23, 2026CVE publishedPublication date reported by the CVE source.
- Aug 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <3.11.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-gjf2-f4jc-69xf selectedcontent reproductionfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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