CVE-2026-23633

Vulnerability Description

In the endpoint:

/username/reponame/settings/hooks/git/:name

the :name parameter:

• Is URL-decoded by macaron routing, allowing decoded slashes (/)
• Is then passed directly to:

git.Repository.Hook("custom_hooks", name)

which internally resolves the path as:

filepath.Join(repoPath, "custom_hooks", name)

Because no path sanitization is applied, supplying ../ sequences allows access to arbitrary paths outside the repository.

As a Result:

• GET: Arbitrary file contents are displayed in the hook edit page textarea (Local File Inclusion).
• POST: Existing files can be overwritten with attacker-controlled content (Arbitrary File Write).

Attack Prerequisites

• The attacker is an authenticated user
• The attacker has Admin or higher privileges on the target repository
• The attacker has the AllowGitHook permission (or is a site administrator)
• The target file is readable/writable by the Gogs process OS permissions

Attack Scenario

1. An attacker (with AllowGitHook + repository Admin privileges) accesses the Git hook edit URL
2. A path containing ../ is supplied in :name, fully URL-encoded using %2f
3. The server resolves custom_hooks/../../... without validation
4. Arbitrary file contents are displayed and existing files can be overwritten

Potential Impact

• Sensitive information disclosure: app.ini, databases, logs, environment variables, etc.
• Configuration or data tampering: Overwriting existing files
• Secondary impact: Extraction of SECRET_KEY and database credentials may allow token forging or further compromise

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-23633 has a CVSS score of 6.5 (Medium). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.13.4); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-23633? CVE-2026-23633 is a medium-severity path traversal vulnerability in gogs.io/gogs (go), affecting versions <= 0.13.3. It is fixed in 0.13.4. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-23633? CVE-2026-23633 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of gogs.io/gogs are affected by CVE-2026-23633? gogs.io/gogs (go) versions <= 0.13.3 is affected.
4. Is there a fix for CVE-2026-23633? Yes. CVE-2026-23633 is fixed in 0.13.4. Upgrade to this version or later.
5. Is CVE-2026-23633 exploitable, and should I be worried? Whether CVE-2026-23633 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-23633 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-23633? Upgrade gogs.io/gogs to 0.13.4 or later.