Cross-Site Scripting (XSS) in Xapian xapian-core (CVE-2026-77643)
Summary
Cross-site scripting in Xapian xapian-core (CVE-2026-77643). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-77643 has been found in Xapian xapian-core.
Risk of unauthorized operations or information disclosure. CVSS score: 4.4/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Xapian xapian-core CVE-2026-77643" on the vendor's site.
CVE-2026-77643 (Xapian xapian-core) — CWE-79 / CVSS v3 4.4
Attack vector: remote (network-reachable)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in Xapian xapian-core.
Check the vendor advisory for the affected versions of Xapian xapian-core.
Severity: Medium (CVSS 4.4/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Xapian xapian-core を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-77643 xapian-core
- Ubuntu UBUNTU-CVE-2026-77643 xapian-core
References
- web cve@mitre.org
- web cve@mitre.org
- web cve@mitre.org
- web nvd.nist.gov
- web github.com