CVE-2025-66407
Weblate has Server-Side Request Forgery vulnerability
Description
Weblate is a web based localization tool. The Create Component functionality in Weblate allows authorized users to add new translation components by specifying both a version control system and a source code repository URL to pull from. However, prior to version 5.15, the repository URL field is not validated or sanitized, allowing an attacker to supply arbitrary protocols, hostnames, and IP addresses, including localhost, internal network addresses, and local filenames. When the Mercurial version control system is selected, Weblate exposes the full server-side HTTP response for the provided URL. This effectively creates a server-side request forgery (SSRF) primitive that can probe internal services and return their contents. In addition to accessing internal HTTP endpoints, the behavior also enables local file enumeration by attempting file:// requests. While file contents may not always be returned, the application’s error messages clearly differentiate between files that exist and files that do not, revealing information about the server’s filesystem layout. In cloud environments, this behavior is particularly dangerous, as internal-only endpoints such as cloud metadata services may be accessible, potentially leading to credential disclosure and full environment compromise. This has been addressed in the Weblate 5.15 release. As a workaround, remove Mercurial from `VCS_BACKENDS`; the Git backend is not affected. The Git backend was already configured to block the file protocol and does not expose the HTTP response content in the error message.
INFO
Published Date :
Dec. 16, 2025, 12:16 a.m.
Last Modified :
Oct. 7, 2026, 7:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Weblate to version 5.15 or later.
- Remove Mercurial from VCS_BACKENDS as a workaround.
- Configure Git backend to block file protocol.
- Ensure HTTP response content is not exposed.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66407.
| URL | Resource |
|---|---|
| https://github.com/WeblateOrg/weblate/pull/17102 | Issue Tracking Patch |
| https://github.com/WeblateOrg/weblate/pull/17103 | Issue Tracking Patch |
| https://github.com/WeblateOrg/weblate/security/advisories/GHSA-hfpv-mc5v-p9mm | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66407 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66407
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66407 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66407 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 07, 2026
Action Type Old Value New Value Added Translation Title: weblate de WeblateOrg, Description: Weblate es una herramienta de localización basada en web. La funcionalidad 'Crear Componente' en Weblate permite a los usuarios autorizados añadir nuevos componentes de traducción especificando tanto un sistema de control de versiones como una URL de repositorio de código fuente de la que extraer. Sin embargo, antes de la versión 5.15, el campo de la URL del repositorio no está validado ni saneado, lo que permite a un atacante suministrar protocolos, nombres de host y direcciones IP arbitrarios, incluyendo localhost, direcciones de red internas y nombres de archivo locales. Cuando se selecciona el sistema de control de versiones Mercurial, Weblate expone la respuesta HTTP completa del lado del servidor para la URL proporcionada. Esto crea efectivamente una primitiva de falsificación de petición del lado del servidor (SSRF) que puede sondear servicios internos y devolver sus contenidos. Además de acceder a puntos finales HTTP internos, el comportamiento también permite la enumeración de archivos locales al intentar peticiones file: //. Aunque el contenido de los archivos no siempre se devuelva, los mensajes de error de la aplicación diferencian claramente entre los archivos que existen y los que no, revelando información sobre la estructura del sistema de archivos del servidor. En entornos de nube, este comportamiento es particularmente peligroso, ya que los puntos finales solo internos, como los servicios de metadatos de la nube, pueden ser accesibles, lo que podría llevar a la divulgación de credenciales y al compromiso total del entorno. Esto ha sido abordado en la versión 5.15 de Weblate. Como solución alternativa, elimine Mercurial de 'VCS_BACKENDS'; el backend de Git no está afectado. El backend de Git ya estaba configurado para bloquear el protocolo de archivo y no expone el contenido de la respuesta HTTP en el mensaje de error. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'WeblateOrg', 'product': 'weblate', 'versions': [{'status': 'affected', 'version': '< 5.15'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2025-66407', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2025-12-16T19:07:51.759310Z'} -
Initial Analysis by [email protected]
Jan. 12, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N Added CWE CWE-918 Added CPE Configuration OR *cpe:2.3:a:weblate:weblate:*:*:*:*:*:*:*:* versions up to (excluding) 5.15 Added Reference Type GitHub, Inc.: https://github.com/WeblateOrg/weblate/pull/17102 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/WeblateOrg/weblate/pull/17103 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/WeblateOrg/weblate/security/advisories/GHSA-hfpv-mc5v-p9mm Types: Vendor Advisory -
New CVE Received by [email protected]
Dec. 16, 2025
Action Type Old Value New Value Added Description Weblate is a web based localization tool. The Create Component functionality in Weblate allows authorized users to add new translation components by specifying both a version control system and a source code repository URL to pull from. However, prior to version 5.15, the repository URL field is not validated or sanitized, allowing an attacker to supply arbitrary protocols, hostnames, and IP addresses, including localhost, internal network addresses, and local filenames. When the Mercurial version control system is selected, Weblate exposes the full server-side HTTP response for the provided URL. This effectively creates a server-side request forgery (SSRF) primitive that can probe internal services and return their contents. In addition to accessing internal HTTP endpoints, the behavior also enables local file enumeration by attempting file:// requests. While file contents may not always be returned, the application’s error messages clearly differentiate between files that exist and files that do not, revealing information about the server’s filesystem layout. In cloud environments, this behavior is particularly dangerous, as internal-only endpoints such as cloud metadata services may be accessible, potentially leading to credential disclosure and full environment compromise. This has been addressed in the Weblate 5.15 release. As a workaround, remove Mercurial from `VCS_BACKENDS`; the Git backend is not affected. The Git backend was already configured to block the file protocol and does not expose the HTTP response content in the error message. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N Added CWE CWE-352 Added Reference https://github.com/WeblateOrg/weblate/pull/17102 Added Reference https://github.com/WeblateOrg/weblate/pull/17103 Added Reference https://github.com/WeblateOrg/weblate/security/advisories/GHSA-hfpv-mc5v-p9mm