CVE-2026-126831 · Infrastructure
NO FIX YET
A stack buffer overflow in cpio occurs when archiving files whose owner or group names exceed 32 characters while writing tar or ustar formats. The unbounded copy corrupts stack memory and crashes the program.
first public Nov 12, 2026 · 1 source
Check it with your coding agent
It reads this page and tells you if your code or app is affected.
Only local users who can run cpio to create tar or ustar archives of files with long owner or group names can trigger the crash. The sources describe a denial of service, not code execution. Systems that never run cpio in these formats can skip it.
Not affected if no-local-users, no-tar-or-ustar-archiving
Who cares cpio, linux, unix
cpio --version to see which version is installed.cpio with -H tar or -H ustar on files with long user or group names.No fix yet, per the sources.
A flaw was found in cpio. A local user can cause a Denial of Service (DoS) by triggering a stack-based buffer overflow when creating archives in tar or ustar formats. When archiving files owned by users or groups with names exceeding 32 characters, cpio copies these names into fixed-size memory without verifying their length. This unbounded copy corrupts stack memory and causes the application to crash.
This page as .md · .json · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
Are you affected?
Ask from here. InfraStack checks the affected versions against your stack and answers in your inbox.
InfraStack checks the affected versions against your stack and answers in Slack, with the evidence and the fix.
InfraStack checks it against your stack and answers on your report, with the evidence and the fix.