MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature. The event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script. Preconditions: - An authenticated MISP user with the ability to create or modify an event graph entry. - A second user (the victim) who views the event graph and triggers the preview popover. Impact: - Execution of arbitrary JavaScript in the victim's browser within the MISP application context. - Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser. - Potential for performing actions on behalf of the victim within the MISP application. Affected: MISP versions prior to the fix (commit applied after v2.5.48).
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA MISP (MISP) Fixed in 2.5.48
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
MISP 2.5.48
6 records Highest priority Priority LOW 6 LOW
Other records, highest priority first
- TI-2026-65615 MISP Tag Collection Save Allows Privilege Escalation via Sibling Model InjectionPriority LOW 39
- TI-2026-65613 MISP Event Delegation Mass Assignment Allows Retargeting Delegation to Arbitrary EventsPriority LOW 39
- TI-2026-65614 MISP: Nested Model Alias Key Bypasses Sanitization to Modify Cross-Tenant RowsPriority LOW 36
Timeline
- 2026-10-02 Threatist record created from CVE-2026-103321
- 2026-10-03 Alias added: GHSA-w4mv-4x7w-vpvv
References
Patch 1
More MISP vulnerabilities
- TI-2025-41517 In MISP before 2.5.28, app/View/Elements/Workflows/executionPath.ctp allows XSS in the workflow execution path. CVSS 3.1CRITICAL 9.0
- TI-2026-65744 MISP TOTP Code Replay Allows Duplicate Authentication Within Validity Period CVSS 4.0CRITICAL 9.3
- TI-2026-54145 Path Traversal in MISP Object Template Resolution During STIX Import and Export in misp-stix library CVSS 4.0HIGH 8.8
- TI-2020-10250 MISP MISP-maltego 1.4.4 incorrectly shares a MISP connection across users in a remote-transform use case. CVSS 3.1CRITICAL 9.8
- TI-2026-59159 MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding CVSS 4.0HIGH 8.7
- TI-2026-58541 MISP LDAP and LinOTP Authentication Bypass via Empty or Invalid Credentials CVSS 4.0CRITICAL 9.5
Sources
- CVE-2026-103321 · CVE Program
- CVE-2026-103321 · NVD
- FIRST EPSS
- GHSA-w4mv-4x7w-vpvv · GitHub Advisory Database · CC BY 4.0
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