Cross-Site Scripting (XSS) in HSC MailInspector (CVE-2026-29964)
Summary
Cross-site scripting in HSC MailInspector (CVE-2026-29964). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
HSC MailInspector v5.3.3-7 contains a Cross-Site Scripting (XSS) vulnerability in the /tap/tap.php endpoint due to improper neutralization of user-controlled input using alternate or obfuscated JavaScript syntax. The endpoint reflects unsanitized user input in HTTP responses without adequate output encoding, allowing a remote attacker to execute arbitrary JavaScript code in the context of a victim's browser.
Source: GitHub Security Advisories (Global) 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-2026-29964 has been found in HSC MailInspector.
Risk of unauthorized operations or information disclosure. CVSS score: 6.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "HSC MailInspector CVE-2026-29964" on the vendor's site.
CVE-2026-29964 (HSC MailInspector) — CWE-79 / CVSS v3 6.1
Attack vector: remote (network-reachable) / unauthenticated
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 HSC MailInspector.
Check the vendor advisory for the affected versions of HSC MailInspector.
Severity: Medium (CVSS 6.1/10). 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 HSC MailInspector を使っているサービスとバージョンを洗い出す。
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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。
References
- advisory cve@mitre.org
- advisory cve@mitre.org
- web nvd.nist.gov
- web hsclabs.com
- web github.com
- web cve@mitre.org