Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 6 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Hardened Images | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | cpio | No fix yet | — |
| Ubuntu 26.04 LTS | cpio | No fix yet | — |
| Ubuntu 24.04 LTS | cpio | No fix yet | — |
| Ubuntu 22.04 LTS | cpio | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | cpio | No fix yet | — |
| Ubuntu Pro 18.04 LTS | cpio | No fix yet | — |
| Ubuntu Pro 16.04 LTS | cpio | No fix yet | — |
| Ubuntu Pro 14.04 LTS | cpio | No fix yet | — |
Advisories 1
- WID-SEC-2026-4551 cpio: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
References
- https://access.redhat.com/security/cve/CVE-2026-126831 vdb-entry
- RHBZ#2571893 issue-tracking