CVE-2026-66485 Uncontrolled Memory Allocation in GNU cpio
A malicious cpio archive can cause a stack overflow and crash the cpio process during extraction, leading to denial of service.
- 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-2026-66485?
CVE-2026-66485 is a medium-severity denial of service 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 an uncontrolled memory allocation in the make_path function at src/makepath.c. The function uses alloca to allocate stack memory based on the length of argpath, which is derived from an archive-controlled pathname during extraction. A malicious cpio archive containing a sufficiently long nested pathname causes an unbounded stack allocation, resulting in a stack overflow and crash of the cpio process. An attacker who can supply a crafted cpio archive to a victim who extracts it can cause a denial of service.
This issue has been fixed in commit 3cd514031371d8aeeaf2048aa10103e02831aaa9
Weakness: CWE-789
Which versions are affected by CVE-2026-66485?
Linux distribution packages (1)
cpio Red Hat:hummingbird:1 | All versions | 0:2.15-10.3.hum1 |
How do I fix CVE-2026-66485?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-66485 being exploited?
There is no known exploitation of CVE-2026-66485 in the wild and no public exploit code.
Sources
Also known as AZL-94692, DEBIAN-CVE-2026-66485, GHSA-mmw4-f4p6-w77q, RHSA-2026:82414, UBUNTU-CVE-2026-66485.