# CVE-2025-66507: GO-2025-4209 - 1Panel , CAPTCHA Bypass via Client-Controlled Flag in github.com/1Panel-dev/1Panel

Source: https://junglewise.ai/threats/cve-2025-66507-1panel-captcha-bypass-via-client-controlled-flag  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-12-09  
License: CC BY 4.0 with a link back

CVE-2025-66507 · Severity: high · CVSS 7.5 · Published 2025-12-09

1Panel is an open-source, web-based control panel for Linux server management. Versions 2.0.13 and below allow an unauthenticated attacker to disable CAPTCHA verification by abusing a client-controlled parameter. Because the server previously trusted this value without proper validation, CAPTCHA protections can be bypassed, enabling automated login attempts and significantly increasing the risk of account takeover (ATO). This issue is fixed in version 2.0.14.

Technologies: [github.com/1Panel-dev/1Panel (Go)](https://junglewise.ai/threats/technologies/github-com-1panel-dev-1panel). Vendors: [Fit2cloud](https://junglewise.ai/threats/vendors/fit2cloud), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2025-66507 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-66507 being exploited in the wild.

**How severe is CVE-2025-66507?** High severity, with a CVSS score of 7.5, published 9 December 2025.

**Which products and versions are affected?** github.com/1Panel-dev/1Panel (Go) SEMVER:introduced=0,fixed=2.0.14, SEMVER:introduced=0,fixed=2.0.14+incompatible; github.com/1Panel-dev/1Panel/core (Go) SEMVER:introduced=0,fixed=0.0.0-20251128030527-ac43f00273be.

**Is there a fix for CVE-2025-66507?** Yes. github.com/1Panel-dev/1Panel (Go): upgrade to 2.0.14, 2.0.14+incompatible or later; github.com/1Panel-dev/1Panel/core (Go): upgrade to 0.0.0-20251128030527-ac43f00273be or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-66507?** Check whether you run Fit2cloud 1panel, github.com/1Panel-dev/1Panel (Go) or github.com/1Panel-dev/1Panel/core (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/1Panel-dev/1Panel (Go): upgrade to 2.0.14, 2.0.14+incompatible or later

  ```sh
  go get github.com/1Panel-dev/1Panel@v2.0.14+incompatible
  ```

- github.com/1Panel-dev/1Panel/core (Go): upgrade to 0.0.0-20251128030527-ac43f00273be or later

  ```sh
  go get github.com/1Panel-dev/1Panel/core@v0.0.0-20251128030527-ac43f00273be
  ```


## Affected products

- Fit2cloud 1panel
- github.com/1Panel-dev/1Panel (Go) SEMVER:introduced=0,fixed=2.0.14, SEMVER:introduced=0,fixed=2.0.14+incompatible
- github.com/1Panel-dev/1Panel/core (Go) SEMVER:introduced=0,fixed=0.0.0-20251128030527-ac43f00273be

## Identifiers

- CVE-2025-66507
- GHSA-qmg5-v42x-qqhq
- GO-2025-4209

## Related threats

- [LXware 1Panel CSRF in panel name management](https://junglewise.ai/threats/cve-2025-34430-lxware-1panel-csrf-in-panel-name-management)
- [LXware 1Panel CSRF in web port configuration](https://junglewise.ai/threats/cve-2025-34429-lxware-1panel-csrf-in-web-port-configuration)
- [LXware 1Panel CSRF in Change Username functionality](https://junglewise.ai/threats/cve-2025-34410-lxware-1panel-csrf-in-change-username-functionality)
- [GO-2025-4207 - 1Panel IP Access Control Bypass via Untrusted X-Forwarded-For Headers in github.com/1Panel-dev/1Panel](https://junglewise.ai/threats/cve-2025-66508-1panel-ip-access-control-bypass-via-untrusted-x-forwarded-for)
- [1Panel agent certificate verification bypass leading to arbitrary command execution](https://junglewise.ai/threats/cve-2025-54424-1panel-agent-certificate-verification-bypass-leading-to-arbitrary)