The script combines those signals into a transparent risk score, then emits findings and prioritized recommendations.

What this script does

check-copyfail.sh is intended as a host-side assessment aid for administrators and infrastructure owners. It gathers local signals related to CVE-2026-31431, evaluates them against the script's built-in logic, and reports an estimated exposure level with supporting findings.

The result is meant to help with investigation and triage. It is not a guarantee that a system is safe, vulnerable, fully patched, or exploitable in practice.

Requirements

• Linux only
• Bash

Usage

Run the actual script filename with a hyphen:

The script comments and embedded help still refer to check_copyfail.sh, but the executable file in this repository is check-copyfail.sh.

Output modes

• default: human-readable report
• --json: structured JSON output
• --quiet: no output, exit code only

Exit codes

• 0: minimal risk
• 1: low risk
• 2: medium risk
• 3: high risk
• 4: critical risk
• 5: execution error or unsupported platform

Notes

• The script does not apply fixes; it only inspects the current system state.
• The script does not load or unload kernel modules, write system files, or change boot or runtime configuration during normal execution.
• On non-Linux systems it exits with code 5.
• The default human-readable report includes short inline explanations for the main result fields.

References

• Xint disclosure write-up: https://xint.io/blog/copy-fail-linux-distributions

Disclaimer

Use this script at your own risk. The maintainers of this repository are not responsible for any damage, loss, operational impact, incorrect assumptions, or decisions made based on the script output.

The script provides a best-effort assessment only. Final responsibility for validating results, confirming whether operating systems are vulnerable, and determining the appropriate remediation or operational response remains with the owner or administrator of the infrastructure.