Cross-Site Scripting (XSS) in MISP (CVE-2026-103662)
Summary
Cross-site scripting in MISP (CVE-2026-103662). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
MISP contains a reflected cross-site scripting (XSS) vulnerability in the legacy taxonomy tag management confirmation forms (add tag and disable tag).
The affected forms echoed a user-supplied tag name value from the request unescaped into the rendered HTML output. An attacker who can induce a site administrator to visit a crafted URL containing a malicious tag name parameter can execute arbitrary JavaScript in the administrator's browser session.
Preconditions:
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The target must be running a MISP instance with the legacy taxonomy tag confirmation views enabled.
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The victim must be an authenticated site administrator.
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The victim must navigate to the attacker-crafted URL (e.g., via a phishing link).
Security impact:
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Execution of arbitrary client-side script in the context of the administrator's browser.
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Potential theft of session tokens, CSRF tokens, or other sensitive data accessible from the page.
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Potential for performing privileged actions on behalf of the administrator within the MISP interface.
Affected versions: <2.5.48.
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-2026-103662 has been found in MISP.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "MISP CVE-2026-103662" on the vendor's site.
CVE-2026-103662 (MISP) — CWE-79
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 MISP.
Check the vendor advisory for the affected versions of MISP.
Severity: ?. 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. Run grep -r 'MISP' . against your dependency files (package-lock.json, requirements.txt, go.sum) 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
grep -r 'MISP' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
MISPを grep し、稼働しているサービス・バージョンを把握する。 -
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
- web github.com
- web nvd.nist.gov
- web github.com