CVE-2026-77643: CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') in Xapian xapian-core
Description
Xapian is an Open Source Search Engine Library, released under the GPL v2+. It is a highly adaptable toolkit which allows developers to easily add advanced indexing and search facilities to their own applications. It has built-in support for several families of weighting models and also supports a rich set of boolean query operators. Security Fix(es): A cross-site scripting vulnerability in queryparser/termgenerator_internal.cc in Xapian xapian-core before 2.1.0 and before 1.4.32 exists due to incomplete HTML escaping by Xapian::MSet::snippet(). NOTE: this issue exists because of a missed corner case of CVE-2018-0499.(CVE-2026-77643)
CVSS v3.1
Score 4.4medium
Affected software
Xapian
xapian-core
pkg:deb/debian/xapian-coreRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Xapian xapian-core contains a CWE-79 improper neutralization of input during web page generation vulnerability due to incomplete HTML escaping in the Xapian::MSet::snippet() function. This flaw exists in versions prior to 2.1.0 and 1.4.32 and was introduced as a missed corner case from a previous vulnerability (CVE-2018-0499). The vulnerability could allow an attacker to inject malicious scripts in generated snippets, potentially leading to cross-site scripting attacks.
Potential Impact
The vulnerability allows for cross-site scripting (XSS) attacks due to improper HTML escaping in snippet generation. This can lead to limited confidentiality and integrity impacts in affected applications that use the vulnerable versions of Xapian xapian-core. The CVSS vector indicates network attack vector, high attack complexity, low privileges required, user interaction required, and scope change, with low confidentiality and integrity impact and no availability impact.
Mitigation Recommendations
A fix is available in Xapian xapian-core versions 2.1.0 and 1.4.32 and later. Users should upgrade to these versions or later to remediate this vulnerability. No additional mitigation is required if the software is updated to these fixed versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-08-20T21:23:30.985Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a8773a6acd9273b49283124
Added to database: 08/20/2026, 21:37:42 UTC
Last enriched: 09/25/2026, 04:46:01 UTC
Last updated: 10/04/2026, 18:53:18 UTC
Views: 90
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