Cross-site scripting via trimmed control-character tag names
Published Aug 6, 2026 · Updated Aug 6, 2026
Cross-site scripting in jsoup 1.14.3 through 1.22.2 allows remote attackers to inject active markup through malformed HTML sanitization. The HTML tokenizer uses trim-based tag-name normalization, so a trailing control character can make a malformed tag inherit another element's raw-text parsing behavior and serialize inert text as markup. Exploitation requires a custom Safelist that permits raw-text elements and user interaction with the serialized output; built-in Safelists are unaffected.
Summary
What happened
Cross-site scripting in jsoup 1.14.3 through 1.22.2 allows remote attackers to inject active markup through malformed HTML sanitization. The HTML tokenizer uses trim-based tag-name normalization, so a trailing control character can make a malformed tag inherit another element's raw-text parsing behavior and serialize inert text as markup. Exploitation requires a custom Safelist that permits raw-text elements and user interaction with the serialized output; built-in Safelists are unaffected.
The record
- CVE
- CVE-2026-71497
- Published
- Aug 6, 2026
- Updated
- Aug 6, 2026
- Vendor
- Jonathan Hedley
- Product
- jsoup
- Classifications
- CWE-79, T1189
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 6, 2026CVE publishedPublication date reported by the CVE source.
- Aug 6, 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=>= 1.14.3, < 1.23.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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