GHSA-9p44-j4g5-cfx5
Trivy Action has a script injection via sourced env file in composite action
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| GitHub Actions | aquasecurity/trivy-action | >= 0.31.0, < 0.34.0 | 0.34.0 |
Details
As written in the advisory (Markdown source, shown as plain text).
Command Injection in aquasecurity/trivy-action via Unsanitized Environment Variable Export
A command injection vulnerability exists in `aquasecurity/trivy-action` due to improper handling of action inputs when exporting environment variables. The action writes `export VAR=<input>` lines to `trivy_envs.txt` based on user-supplied inputs and subsequently sources this file in `entrypoint.sh`.
Because input values are written without appropriate shell escaping, attacker-controlled input containing shell metacharacters (e.g., `$(...)`, backticks, or other command substitution syntax) may be evaluated during the sourcing process. This can result in arbitrary command execution within the GitHub Actions runner context.
**Severity:**
Moderate
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
CWE-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)
**Impact:**
Successful exploitation may lead to arbitrary command execution in the CI runner environment.
**Affected Versions:**
* Versions >= 0.31.0 and <= 0.33.1
* Introduced in commit `7aca5ac`
**Affected Conditions:**
The vulnerability is exploitable when a consuming workflow passes attacker-controlled data into any action input that is written to `trivy_envs.txt`. Access to user input is required by the malicious actor.
A representative exploitation pattern involves incorporating untrusted pull request metadata into an action parameter. For example:
```yaml
- uses: aquasecurity/[email protected]
with:
output: "trivy-${{ github.event.pull_request.title }}.sarif"
```
If the pull request title contains shell syntax, it may be executed when the generated environment file is sourced.
**Not Affected:**
* Workflows that do not pass attacker-controlled data into `trivy-action` inputs
* Workflows that upgrade to a patched version that properly escapes shell values or eliminates the `source ./trivy_envs.txt` pattern
* Workflows where user input is not accessible.
**Call Sites:**
* `action.yaml:188` — `set_env_var_if_provided` writes unescaped `export` lines
* `entrypoint.sh:9` — sources `./trivy_envs.txt`
References
External links from the advisory. They lead to third-party sites.
- https://github.com/aquasecurity/trivy-action/security/advisories/GHSA-9p44-j4g5-cfx5
- https://nvd.nist.gov/vuln/detail/CVE-2026-26189
- https://github.com/aquasecurity/trivy-action/commit/7aca5acc9500b463826cc47a47a65ad7d404b045
- https://github.com/aquasecurity/trivy-action/commit/bc61dc55704e2d5704760f3cdab0d09acf16e4ca
- https://github.com/aquasecurity/trivy-action