CVE-2026-103388
MISP Stored Cross-Site Scripting via JavaScript URL in Galaxy Cluster Source Field
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
-
Attacker must hold galaxy editor privileges (local or via sync).
-
Victim must view the affected cluster and click the malicious link.
Impact:
-
Stored cross-site scripting (XSS) in the victim's browser.
-
Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Active
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
MISP Stored Cross-Site Scripting via JavaScript URL in Galaxy Cluster Source Field
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
-
Attacker must hold galaxy editor privileges (local or via sync).
-
Victim must view the affected cluster and click the malicious link.
Impact:
-
Stored cross-site scripting (XSS) in the victim's browser.
-
Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
- Record
CVE-2026-103388- CVSS 4.0
- 6.2 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-89964
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
-
Attacker must hold galaxy editor privileges (local or via sync).
-
Victim must view the affected cluster and click the malicious link.
Impact:
-
Stored cross-site scripting (XSS) in the victim's browser.
-
Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
- Record
EUVD-2026-89964- CVSS 4.0
- 6.2 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-ccjm-jpcq-p5hf
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored...
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
-
Attacker must hold galaxy editor privileges (local or via sync).
-
Victim must view the affected cluster and click the malicious link.
Impact:
-
Stored cross-site scripting (XSS) in the victim's browser.
-
Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
- Record
GHSA-ccjm-jpcq-p5hf- CVSS 4.0
- 6.2 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
-
Attacker must hold galaxy editor privileges (local or via sync).
-
Victim must view the affected cluster and click the malicious link.
Impact:
-
Stored cross-site scripting (XSS) in the victim's browser.
-
Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
- Record
CVE-2026-103388- CVSS 4.0
- 6.2 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
MISP Stored Cross-Site Scripting via JavaScript URL in Galaxy Cluster Source Field
MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.
When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.
Preconditions:
-
Attacker must hold galaxy editor privileges (local or via sync).
-
Victim must view the affected cluster and click the malicious link.
Impact:
-
Stored cross-site scripting (XSS) in the victim's browser.
-
Potential session theft, credential harvesting, or unauthorized actions within the MISP application.
Affected: <2.5.48.
- Record
CVE-2026-103388- CVSS 4.0
- 6.2 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-103388 is a medium vulnerability (CVSS 6.2) in Misp, published September 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 15th percentile. No source names a fixed version.