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 versions from 1.14.3 up to but not including 1.23.1. The issue arises when the HTML parser incorrectly handles malformed tag names ending with control characters, causing misparsing that can lead to active markup emission instead of inert text. This vulnerability affects custom Safelists that allow certain raw-text elements, while jsoup's built-in Safelists are not impacted. The vulnerability is fixed in version 1.23.1.
AI Analysis
Technical Summary
jsoup, a Java library for HTML parsing, versions >=1.14.3 and <1.23.1 contain a vulnerability where malformed tag names ending in control characters cause the parser to misinterpret the tag's behavior. When using custom Safelists that permit certain raw-text elements, this misparsing can result in content that should be treated as inert text being output as active markup after serialization, potentially enabling cross-site scripting (CWE-79). The built-in Safelists are unaffected. The issue is resolved in version 1.23.1.
Potential Impact
This vulnerability can lead to cross-site scripting attacks when custom Safelists are used, allowing an attacker to inject active markup that could execute in the context of a user's browser. The impact is limited to scenarios where custom Safelists permit certain raw-text elements and malformed input is processed. The built-in Safelists do not expose this risk. The CVSS score is 4.7 (medium severity), reflecting limited impact and the requirement for user interaction.
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 until the upgrade is applied. No other mitigations are specified or required.
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 versions from 1.14.3 up to but not including 1.23.1. The issue arises when the HTML parser incorrectly handles malformed tag names ending with control characters, causing misparsing that can lead to active markup emission instead of inert text. This vulnerability affects custom Safelists that allow certain raw-text elements, while jsoup's built-in Safelists are not impacted. The vulnerability is fixed in version 1.23.1.
CVSS v3.1
Score 4.7medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
jsoup, a Java library for HTML parsing, versions >=1.14.3 and <1.23.1 contain a vulnerability where malformed tag names ending in control characters cause the parser to misinterpret the tag's behavior. When using custom Safelists that permit certain raw-text elements, this misparsing can result in content that should be treated as inert text being output as active markup after serialization, potentially enabling cross-site scripting (CWE-79). The built-in Safelists are unaffected. The issue is resolved in version 1.23.1.
Potential Impact
This vulnerability can lead to cross-site scripting attacks when custom Safelists are used, allowing an attacker to inject active markup that could execute in the context of a user's browser. The impact is limited to scenarios where custom Safelists permit certain raw-text elements and malformed input is processed. The built-in Safelists do not expose this risk. The CVSS score is 4.7 (medium severity), reflecting limited impact and the requirement for user interaction.
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 until the upgrade is applied. No other mitigations are specified or required.
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
- Remediation Level
- null
Threat ID: 6a750711bf8831d5395f5e17
Added to database: 08/06/2026, 22:13:37 UTC
Last enriched: 08/06/2026, 22:27:44 UTC
Last updated: 08/07/2026, 02:05:53 UTC
Views: 4
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