CVE-2026-10856
MEDIUM 5.1A URL validation flaw in the MISP dashboard button widget allowed a crafted relative-looking URL to be accepted as a local path while being interpreted by browsers as an external URL. The validation rejected URLs containing an explicit scheme, host, or user component, but did not reject paths beginning with a slash followed by a backslash, such as /\example.com. Some browsers normalize backslashes in URLs as forward slashes, which can turn this into a scheme-relative external navigation target. In addition, the generated href concatenated the reconstructed URL with the original URL, increasing the possibility of unsafe or malformed link generation. An attacker able to configure or influence a dashboard button URL could craft a button that appears to point inside the application but redirects users to an attacker-controlled site when clicked. This could be used for phishing, credential theft, or social engineering. The patch fixes the issue by rejecting empty paths and paths starting with /\, and by emitting only the reconstructed validated URL in the anchor href.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 4th percentile
Impact if exploited
5.1CVSS 4.0 · MEDIUM
- ConfidentialityLow
- IntegrityNone
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Weakness (CWE)
- CWE-601
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/U:Green