MISP Reflected Cross-Site Scripting via Unsanitized Analyst Data Seed Parameter (CVE-2026-103664) | HOL Guard CVE

Medium · CVSS 4.8CVE-2026-103664

MISP Reflected Cross-Site Scripting via Unsanitized Analyst Data Seed Parameter

Answer in brief

CVE-2026-103664 records a Medium severity (CVSS 4.8) vulnerability in MISP Reflected Cross-Site Scripting via Unsanitized Analyst Data Seed Parameter. The current sources do not mark it as known exploited. The current feed maps MISP/MISP (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 1, 2026Updated Oct 1, 2026Source checked Oct 1, 2026First seen by HOL Oct 1, 2026Material review Oct 1, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.8
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 4.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps MISP/MISP (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
MISP/MISPgeneric	>=0 <2.5.48	2.5.48

Recommended response

Check inventory. Check lockfiles and deployed manifests for MISP/MISP.
Review the reported fix. Source-reported solution: The vulnerability is remediated by enforcing integer type on the seed parameter at both the controller layer and the view/template layer. Casting the value to an integer ensures that any non-numeric input (including script payloads) is neutralized before it reaches the inline JavaScript context, eliminating the injection vector.

Evidence timeline and material changes

Published upstream
Oct 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 1, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 1, 2026

Sources and claim methodology

GitHub security advisorygithub.com

Upstream source description

MISP contains a reflected cross-site scripting (XSS) vulnerability in the analyst data notes panel. The seed path parameter, supplied by the user via the URL, was passed directly into inline JavaScript within the rendered HTML response without any sanitization or type enforcement. An attacker who can convince an authenticated MISP user to navigate to a crafted URL (for example, via a phishing link) can inject arbitrary JavaScript that executes in the victim's browser context. This may allow the attacker to read session tokens, manipulate the page, or perform actions on behalf of the victim. Preconditions: - The victim must be authenticated to MISP and access the analyst data view for an attribute or object. - The attacker must supply a malicious seed value in the URL path. Impact: - Execution of arbitrary JavaScript in the victim's browser session. - Potential theft of session credentials or sensitive data visible in the page. - Manipulation of the analyst data interface. Affected: MISP versions prior to the fix (commit 58925dbf0, post v2.5.48).

Quoted source text, attributed separately from HOL analysis.