CVE-2026-71497: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in jhy jsoup
A cross-site scripting (XSS) vulnerability exists in jsoup, a Java HTML parsing library, in versions from 1.14.3 up to but not including 1.23.1. The issue arises when the parser incorrectly handles malformed tag names ending with control characters, causing misparsing that can lead to active markup being emitted instead of inert text when using custom Safelists that allow certain raw-text elements. The built-in Safelists are not affected. This vulnerability has a medium severity score and is fixed in version 1.23.1.
AI Analysis
Technical Summary
jsoup versions >=1.14.3 and <1.23.1 contain a CWE-79 cross-site scripting vulnerability due to improper neutralization of input during web page generation. Specifically, the HTML parser mishandles malformed tag names ending in control characters, causing tags to behave as different elements. When custom Safelists permit certain raw-text elements, this misparsing can result in content that should be inert text being serialized as active markup, potentially enabling XSS attacks. The issue does not affect jsoup's built-in Safelists and is resolved in version 1.23.1.
Potential Impact
This vulnerability could allow an attacker to inject active markup via malformed HTML input when custom Safelists are used, potentially leading to cross-site scripting attacks. The impact is limited to scenarios where custom Safelists permit certain raw-text elements and the vulnerable jsoup versions are used. The built-in Safelists are not vulnerable, reducing the risk in typical usage scenarios.
Mitigation Recommendations
Upgrade jsoup to version 1.23.1 or later, where this vulnerability is fixed. Avoid using custom Safelists that permit raw-text elements if upgrading is not immediately possible. Since no official patch link or vendor advisory is provided, verify the fix by consulting the official jsoup release notes or repository.
CVE-2026-71497: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in jhy jsoup
Description
A cross-site scripting (XSS) vulnerability exists in jsoup, a Java HTML parsing library, in versions from 1.14.3 up to but not including 1.23.1. The issue arises when the parser incorrectly handles malformed tag names ending with control characters, causing misparsing that can lead to active markup being emitted instead of inert text when using custom Safelists that allow certain raw-text elements. The built-in Safelists are not affected. This vulnerability has a medium severity score and is fixed in version 1.23.1.
CVSS v3.1
Score 4.7medium
Affected software
jhy
jsoup
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
jsoup versions >=1.14.3 and <1.23.1 contain a CWE-79 cross-site scripting vulnerability due to improper neutralization of input during web page generation. Specifically, the HTML parser mishandles malformed tag names ending in control characters, causing tags to behave as different elements. When custom Safelists permit certain raw-text elements, this misparsing can result in content that should be inert text being serialized as active markup, potentially enabling XSS attacks. The issue does not affect jsoup's built-in Safelists and is resolved in version 1.23.1.
Potential Impact
This vulnerability could allow an attacker to inject active markup via malformed HTML input when custom Safelists are used, potentially leading to cross-site scripting attacks. The impact is limited to scenarios where custom Safelists permit certain raw-text elements and the vulnerable jsoup versions are used. The built-in Safelists are not vulnerable, reducing the risk in typical usage scenarios.
Mitigation Recommendations
Upgrade jsoup to version 1.23.1 or later, where this vulnerability is fixed. Avoid using custom Safelists that permit raw-text elements if upgrading is not immediately possible. Since no official patch link or vendor advisory is provided, verify the fix by consulting the official jsoup release notes or repository.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-06T19:56:23.726Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a750711bf8831d5395f5e17
Added to database: 08/06/2026, 22:13:37 UTC
Last enriched: 08/14/2026, 16:17:17 UTC
Last updated: 09/21/2026, 22:01:37 UTC
Views: 72
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