How severe is CVE-2023-49291?

CVE-2023-49291 has a CVSS score of 9.3/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-49291?

CVE-2023-49291 affects the following packages: tj-actions/branch-names (GitHub Actions). Ecosystems affected: GitHub Actions.

How do I fix CVE-2023-49291?

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 CVE-2023-49291 is resolved across your whole dependency graph.

How do I detect CVE-2023-49291 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 CVE-2023-49291 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-2023-49291?

O3 pinpoints whether CVE-2023-49291 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-2023-49291 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2023-49291, 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 CVE-2023-49291?

CVE-2023-49291 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 CVE-2023-49291 published, and has it been updated?

CVE-2023-49291 was published on December 4, 2023 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-2023-49291

CRITICAL

Improper Sanitization of Branch Name Leads to Arbitrary Code Injection

Also known asGHSA-8v8w-v8xg-79rf

Published

Dec 4, 2023

Updated

Apr 2, 2026

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

tj-actions/branch-names is a Github action to retrieve branch or tag names with support for all events. The tj-actions/branch-names GitHub Actions improperly 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. As a result an attacker can use this vulnerability to steal secrets from or abuse GITHUB_TOKEN permissions. This vulnerability has been addressed in version 7.0.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.

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 CVE-2023-49291 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-2023-49291 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-2023-49291. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

tj-actions/branch-names is a Github action to retrieve branch or tag names with support for all events. The `tj-actions/branch-names` GitHub Actions improperly 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. As a result an attacker can use this vulnerability to steal secrets from or abuse `GITHUB_TOKEN` permissions. This vulnerability has been addressed in version 7.0.7. Users are advised to upg

O3 Security · Impact-Aware SCA

Is CVE-2023-49291 in your dependencies?

O3 detects CVE-2023-49291 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