CVE-2025-66407
MediumCVSS 5.0Exploitation Probability (EPSS)
Low risk14th percentile - higher than 14% of all known CVEs
Summary
Weblate prior to version 5.15 does not validate or sanitize the repository URL field in the Create Component functionality, allowing an attacker to supply arbitrary protocols, hostnames, and IP addresses, including localhost and internal network addresses. When the Mercurial version control system is selected, Weblate exposes the full server-side HTTP response for the provided URL, creating a server-side request forgery (SSRF) primitive that can probe internal services and return their contents. Additionally, error messages enable local file enumeration via file:// requests, and in cloud environments internal-only endpoints such as cloud metadata services may be accessible.
Risk Assessment
The vulnerability allows an attacker to access internal network services and server files, and in cloud environments may lead to credential disclosure and full environment compromise. The risk is particularly high when Weblate runs in cloud infrastructure with access to metadata services.
Recommendation
Upgrade Weblate to version 5.15 or later. If upgrading is not possible, remove Mercurial from VCS_BACKENDS — the Git backend is not affected as it blocks the file protocol and does not expose HTTP response content in error messages.
Other vulnerabilities in Weblate
See all- CVE-2026-41654High
Weblate is a web-based localization tool. Prior to version 5.17.1, an authenticated user with project.add permissions could import a crafted project backup ZIP containing an attacker-chosen repo URL, potentially leading to data exposure.
- CVE-2026-21889High
Weblate is a web based localization tool. Prior to 5.15.2, the screenshot images were served directly by the HTTP server without proper access control. This could allow an unauthenticated user to access screenshots after guessing their filename. This vulnerability is fixed in 5.15.2.
- CVE-2025-64725Critical
Weblate before version 5.15 allows accepting an invitation opened by a different user. Version 5.15 contains a patch.
- CVE-2026-86035High
Weblate 4.11.1 through 2026.7.1 contains an argument-injection vulnerability in its Mercurial backend. Repository filenames beginning with - could be interpreted as Mercurial options instead of literal paths. An authenticated user with project-scoped component.edit permission could exploit this through a Mercurial-backed RESX component using the Update RESX files add-on, potentially executing arbitrary commands with the privileges of the Weblate service account. This issue has been patched in version 2026.8.
- CVE-2026-77573Low
Weblate prior to 2026.8 allows a user with permission to manage component repository URLs to perform SSRF against internal services through DNS rebinding during VCS operations. Hostname validation uses the first DNS resolution, but VCS clients perform a separate lookup, allowing redirection to an internal address.
- CVE-2026-77507Medium
Weblate prior to version 2026.8 does not apply permission checks in object-scoped RSS feeds, allowing unauthorized users to read change-history metadata from private projects and restricted components. On installations with anonymous access, metadata can be retrieved without authentication. This issue is fixed in version 2026.8.
- CVE-2026-62326Medium
Weblate prior to version 2026.7 allows a user with the "Edit source" role to store a malicious regular expression in a source string's flags that is executed without any timeout, allowing them to stall requests and deny service. This issue is fixed in version 2026.7.
- CVE-2026-62249Medium
Weblate prior to version 2026.7 allows an authenticated user with access to a project to retrieve the change history of restricted components in that project through nested API change endpoints, even without permission to view those components directly. This issue is fixed in version 2026.7.
- CVE-2026-61792High
Weblate is a web-based continuous localization platform. In versions prior to 2026.7, a project administrator can read files outside their repository through the App store metadata download feature, which resolves attacker-influenced paths without confining them to the repository. This is an incomplete fix for CVE-2026-34242, allowing arbitrary file read. A user with project-admin privileges can disclose file contents on the host. Fixed in 2026.7.
- CVE-2026-61790Medium
Weblate prior to version 2026.7 does not enforce two-factor authentication (2FA) requirements for site-wide global permissions, even though a team can require 2FA for its members. A user belonging to a team with 2FA enforcement receives global permissions without 2FA configured, potentially including access to the site management interface. This issue is fixed in version 2026.7.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS