CVE-2026-66486 Improper Output Encoding in GNU cpio
Attackers can inject terminal control sequences or forge listing entries via crafted cpio archives, affecting users viewing archive contents.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-66486?
CVE-2026-66486 is a medium-severity vulnerability in GNU cpio, published on 10 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed.
This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30
Weakness: CWE-116
Which versions are affected by CVE-2026-66486?
How do I fix CVE-2026-66486?
Apply the vendor's patch.
Is CVE-2026-66486 being exploited?
There is no known exploitation of CVE-2026-66486 in the wild and no public exploit code.
Sources
Also known as AZL-94689, DEBIAN-CVE-2026-66486, GHSA-p5w5-qcg3-g8gx, OESA-2026-3540, UBUNTU-CVE-2026-66486.