Is CVE-2026-55158 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-55158 being exploited in the wild.

How severe is CVE-2026-55158?

Critical severity, with a CVSS score of 9.1, published 15 September 2026.

Which products and versions are affected?

wktk/conflibot (GitHub Actions) < 1.2.1; Wktk Conflibot < 1.2.1.

Is there a fix for CVE-2026-55158?

A patch was published on 2026-06-11: Fixed in v1.2.1 and v2.0.0; commits 59e255c and 0107ac6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-55158 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-55158?

Check whether you run wktk/conflibot (GitHub Actions) or Wktk Conflibot at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-55158: conflibot command injection in pull request branch names

Q: Is there a fix for CVE-2026-55158?

A patch was published on 2026-06-11: Fixed in v1.2.1 and v2.0.0; commits 59e255c and 0107ac6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-55158 attacked?

It is attacked over the network, in a web application.

Q: Am I affected by CVE-2026-55158?

Check whether you run wktk/conflibot (GitHub Actions) or Wktk Conflibot at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-55158 · Severity: critical · CVSS 9.1 · Published 2026-09-15

conflibot is a GitHub Actions workflow tool that automatically detects merge conflicts in pull requests. Versions before 1.2.1 construct git commands by concatenating user-controlled pull request branch names into shell commands without sanitization. An attacker can open a pull request with a malicious branch name containing shell metacharacters to execute arbitrary commands on the runner, potentially exfiltrating repository secrets and write-scoped tokens or pushing malicious code to the repository.

Vendors: GitHub Actions.

Quick answers

Is CVE-2026-55158 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-55158 being exploited in the wild.
How severe is CVE-2026-55158?: Critical severity, with a CVSS score of 9.1, published 15 September 2026.
Which products and versions are affected?: wktk/conflibot (GitHub Actions) < 1.2.1; Wktk Conflibot < 1.2.1.
Is there a fix for CVE-2026-55158?: A patch was published on 2026-06-11: Fixed in v1.2.1 and v2.0.0; commits 59e255c and 0107ac6 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-55158 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-55158?: Check whether you run wktk/conflibot (GitHub Actions) or Wktk Conflibot at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

conflibot is vulnerable to OS command injection (CWE-78) in git command construction. The action builds git commands via string interpolation of pull request branch names (head.ref) and executes them through a shell, allowing shell metacharacters (backticks, $(), ;, |, &) in branch names to be interpreted as command syntax. Under the recommended pull_request_target event workflow, the job runs with write-scoped GITHUB_TOKEN and repository secrets in the environment, making the attack highly impactful. Exploitation requires only opening a pull request with a crafted branch name—no special privileges or user interaction is needed. The fix (v1.2.1 and v2.0.0) eliminates the shell by using execFile/spawn with argument arrays, ensuring branch names are treated as literal data. v2.0.0 additionally references pull requests by number through refs/pull/<n>/head instead of branch names.

Affected products

wktk conflibot < 1.2.1

Identifiers

CVE-2026-55158
GHSA-2qvg-qr73-mqxp

Timeline

2026-06-10: disclosed: Published to GitHub Advisory Database as GHSA-2qvg-qr73-mqxp
2026-06-11: patched: Fixed in v1.2.1 and v2.0.0; commits 59e255c and 0107ac6

References

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