---
id: CVE-2026-57862
title: Kanboard 1.2.52 and prior SSRF Filter Bypass via Hexadecimal IP Notation
summary: >-
  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
  hexadeci…
severity: high
cvss: 8.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-918
vendor: Kanboard
product: Kanboard
affected:
  - Kanboard <= 1.2.52
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-30T17:30:40.371820Z'
exploitAvailable: true
published: '2026-07-30'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T14:17:54.637Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-57862'
references:
  - url: 'https://github.com/kanboard/kanboard'
    label: Product Repository
  - url: 'https://gist.github.com/sermikr0/67c8acfc395e465127e729dc309da3ae'
    label: GitHub Gist
  - url: >-
      https://www.vulncheck.com/advisories/kanboard-and-prior-ssrf-filter-bypass-via-hexadecimal-ip-notation
tags:
  - cve.org
  - exploit-available
epss: 0.00293
epssPercentile: 0.22154
ingestedAt: '2026-09-24T15:45:56.726Z'
---

## Overview

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.

## Affected

- `Kanboard <= 1.2.52`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.