CVE-2026-57862

Description

Kanboard 1.2.52 and prior contains a server-side request forgery vulnerability that allows authenticated users to bypass SSRF protections by supplying hexadecimal IP address notation in user-controlled URLs. Attackers can submit hexadecimal-encoded internal IP addresses through the web link creation feature, causing cURL to resolve and connect to internal network resources such as cloud instance metadata services, localhost services, and RFC1918 addresses while the isPrivateURL() filter in app/Core/Http/Client.php incorrectly treats the input as safe due to FILTER_VALIDATE_IP rejecting non-dotted-decimal notation.

References

https://www.vulncheck.com/advisories/kanboard-and-prior-ssrf-filter-bypass-via-hexadecimal-ip-notation

https://github.com/kanboard/kanboard

https://gist.github.com/sermikr0/67c8acfc395e465127e729dc309da3ae

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4