CVE-2026-25761

The Super-linter GitHub Action is vulnerable to command injection via crafted filenames. When this action is used in downstream GitHub Actions workflows, an attacker can submit a pull request that introduces a file whose name contains shell command substitution syntax, such as $(...). In affected Super-linter versions, runtime scripts may execute the embedded command during file discovery processing, enabling arbitrary command execution in the workflow runner context. This can be used to disclose the job’s GITHUB_TOKEN depending on how the workflow configures permissions.

Details

The issue appears originates in the logic that scans the repository for changed files to check.

1. Use a workflow that runs Super-linter on pull_request events.
2. Open a pull request that adds a new file with a crafted filename containing command substitution and an outbound request that includes $GITHUB_TOKEN.
3. Run the workflow.

• Arbitrary command execution in the context of the workflow run that invokes Super-linter (triggered by attacker-controlled filenames in a PR).
• Credential exposure / misuse: the injected command can read environment variables available to the action, including GITHUB_TOKEN.

The level of exposure depends on the source of the pull request.

To actively exploit the vulnerability, an attacker needs have the ability to run workflows without any approval from the repository admin.

Also, the GITHUB_TOKEN needs to have unconstrained access to repository resources. Even in that case, for pull request coming from forked repositories, no secrets are passed to the forked repository when running workflows triggered by pull_request events, and the GITHUB_TOKEN drops and write permission on the source repository source.

Finally, although not specific to this vulnerability, we recommend auditing workflow_call and pull_request_target workflows because they can lead to compromise, regardless of whether you're using Super-linter, or not, as explained by this GitHub Enterprise doc.

Untrusted input is inserted into a command that is later executed by the application, allowing the attacker to alter the intent of that command. Typical impact: arbitrary command execution in the application's environment.

CVE-2026-25761 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. 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 (8.3.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-25761? CVE-2026-25761 is a high-severity command injection vulnerability in super-linter/super-linter (actions), affecting versions >= 6.0.0, < 8.3.1. It is fixed in 8.3.1. Untrusted input is inserted into a command that is later executed by the application, allowing the attacker to alter the intent of that command.
2. How severe is CVE-2026-25761? CVE-2026-25761 has a CVSS score of 8.8 (High). 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 packages are affected by CVE-2026-25761?
   • super-linter/super-linter (actions) (versions >= 6.0.0, < 8.3.1)
   • super-linter/super-linter/slim (actions) (versions >= 6.0.0, < 8.3.1)
4. Is there a fix for CVE-2026-25761? Yes. CVE-2026-25761 is fixed in 8.3.1. Upgrade to this version or later.
5. Is CVE-2026-25761 exploitable, and should I be worried? Whether CVE-2026-25761 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-2026-25761 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-2026-25761?
   • Upgrade super-linter/super-linter to 8.3.1 or later
   • Upgrade super-linter/super-linter/slim to 8.3.1 or later