What is CVE-2026-26189?

Trivy Action runs Trivy as GitHub action to scan a Docker container image for vulnerabilities. A command injection vulnerability exists in `aquasecurity/trivy-action` versions 0.31.0 through 0.33.1 due to improper handling of action inputs when exporting environment variables. The action writes `export VAR= ` 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

How severe is CVE-2026-26189?

CVE-2026-26189 has a CVSS score of 5.9/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-26189?

CVE-2026-26189 affects the following packages: aquasecurity/trivy-action (GitHub Actions). Ecosystems affected: GitHub Actions.

How do I fix CVE-2026-26189?

Update aquasecurity/trivy-action to 0.34.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-26189 is resolved across your whole dependency graph.

How do I detect CVE-2026-26189 in my GitHub Actions dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aquasecurity/trivy-action. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-26189 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-26189?

O3 pinpoints whether CVE-2026-26189 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-26189 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-26189 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-26189?

CVE-2026-26189 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 67th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-26189?

CVE-2026-26189 is classified as OS Command Injection (CWE-78). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-26189 published, and has it been updated?

CVE-2026-26189 was published on February 19, 2026 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 GitHub Actions

CVE-2026-26189

MEDIUM

Trivy Action has a script injection via sourced env file in composite action

Also known asGHSA-9p44-j4g5-cfx5

Published

Feb 19, 2026

Updated

Apr 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk67th percentile+1.21%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

📦aquasecurity/trivy-action

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects GitHub Actions packages — download data is not available via public APIs for these ecosystems.

Description

Trivy Action runs Trivy as GitHub action to scan a Docker container image for vulnerabilities. A command injection vulnerability exists in aquasecurity/trivy-action versions 0.31.0 through 0.33.1 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. Version 0.34.0 contains a patch for this issue. 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. 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, and workflows where user input is not accessible are not affected.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦GitHub Actions	`aquasecurity/trivy-action`	≥ 0.31.0&&< 0.34.0	0.34.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aquasecurity/trivy-action. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update aquasecurity/trivy-action to 0.34.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-26189 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-26189 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-26189. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Trivy Action runs Trivy as GitHub action to scan a Docker container image for vulnerabilities. A command injection vulnerability exists in `aquasecurity/trivy-action` versions 0.31.0 through 0.33.1 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

O3 Security · Impact-Aware SCA

Is CVE-2026-26189 in your dependencies?

O3 detects CVE-2026-26189 across GitHub Actions dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works