# CVE-2025-52576: Kanboard vulnerable to Username Enumeration via Login Behavior and Bruteforce Protection Bypass

> Attackers can enumerate valid usernames and bypass IP-based brute-force protections by abusing trusted HTTP headers in Kanboard.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Jun 2025
- **Updated:** 25 Jun 2025
- **Also known as:** GHSA-qw57-7cx6-wvp7

## What is CVE-2025-52576?

CVE-2025-52576 is a medium-severity vulnerability in kanboard, published on 25 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Kanboard is project management software that focuses on the Kanban methodology. Prior to version 1.2.46, Kanboard is vulnerable to username enumeration and IP spoofing-based brute-force protection bypass. By analyzing login behavior and abusing trusted HTTP headers, an attacker can determine valid usernames and circumvent rate-limiting or blocking mechanisms. Any organization running a publicly accessible Kanboard instance is affected, especially if relying on IP-based protections like Fail2Ban or CAPTCHA for login rate-limiting. Attackers with access to the login page can exploit this flaw to enumerate valid usernames and bypass IP-based blocking mechanisms, putting all user accounts at higher risk of brute-force or credential stuffing attacks. Version 1.2.46 contains a patch for the issue.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2025-52576?

It affects 1 product.


Products: Kanboard Kanboard.

## How do I fix CVE-2025-52576?

No fix has been published for CVE-2025-52576 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-52576 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-52576 exists.

## Other vulnerabilities in kanboard

- [CVE-2026-21881](https://insights.sbomify.com/CVE-2026-21881/): Kanboard is Vulnerable to Reverse Proxy Authentication Bypass (critical 9.1)
- [CVE-2025-55010](https://insights.sbomify.com/CVE-2025-55010/): Kanboard Authenticated Admin Remote Code Execution via Unsafe Deserialization of Events (critical 9.1)
- [CVE-2024-51747](https://insights.sbomify.com/CVE-2024-51747/): Arbitrary File Read and Delete in kanboard (critical 9.1)
- [CVE-2024-51748](https://insights.sbomify.com/CVE-2024-51748/): Remote code execution through language setting in kanboard (critical 9.1)
- [CVE-2017-12850](https://insights.sbomify.com/CVE-2017-12850/): Business logic in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-52576 and fix it if it is affected.

What it is: CVE-2025-52576 is a medium-severity vulnerability in kanboard, published on 25 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-52576 exists.

Affected product: kanboard. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-52576/ (Markdown: https://insights.sbomify.com/CVE-2025-52576/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-52576
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-52576
- OSV: https://osv.dev/vulnerability/CVE-2025-52576

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-52576/
Summaries are generated and may contain mistakes; the official description above is the record.