MISP: JavaScript Injection via Remote Tag ID in Event Preview Inline Handler
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- None · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
MISP contains a cross-site scripting (XSS) vulnerability in the remote event preview page. When a linked (remote) MISP server is configured, the event preview renders tag identifiers inside an inline JavaScript onclick attribute. The tag ID value was HTML-escaped but not sanitized for the JavaScript string context, meaning a malicious linked server could supply a tag ID containing characters (such as a single quote) that break out of the JavaScript string literal and inject arbitrary script. Preconditions: - A linked/remote MISP server is configured and connected to the local instance. - The linked server supplies a crafted tag ID in an event. - An authenticated user views the event preview and interacts with the affected tag element. Impact: - Arbitrary JavaScript execution in the context of the viewing user's browser session, potentially allowing session hijacking, data exfiltration, or unauthorized actions on behalf of the user. Affected versions: MISP prior to the fix commit (v2.5.48 or later, exact boundary unconfirmed).
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
8 records Highest priority Priority LOW 8 LOW
Other records, highest priority first
- TI-2026-66152 MISP Correlation Authorization Bypass Exposes Restricted Event and Attribute DataPriority LOW 31
- TI-2026-66150 MISP Decaying Model Import Mass Assignment Allows Cross-Organization Model Overwrite and Default FlaggingPriority LOW 31
- TI-2026-66148 MISP TAXII Object Viewer Stored XSS via Unescaped JSON OutputPriority LOW 28
Timeline
- 2026-10-02 Threatist record created from CVE-2026-104907
- 2026-10-03 Alias added: GHSA-4g8m-xfv2-jhr3
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-2026-104907 · CVE Program
- CVE-2026-104907 · NVD
- FIRST EPSS
- GHSA-4g8m-xfv2-jhr3 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences