Log in Start free

Vulnerability · Published Aug 10, 2026 · Assigned by CERT-PL

CVE-2026-66485Uncontrolled Memory Allocation in GNU cpio

Medium 4.6

In plain English

A medium-severity security flaw in cpio from GNU. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)4.6Medium
Exploit odds (30 days)0.2%top 91.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12cpiono fix listedDEBIAN-CVE-2026-66485
Debian:13cpiono fix listedDEBIAN-CVE-2026-66485
Debian:14cpiono fix listedDEBIAN-CVE-2026-66485
Ubuntu:22.04:LTScpio2.13+dfsg-7ubuntu0.2UBUNTU-CVE-2026-66485
Ubuntu:22.04:LTScpio2.13+dfsg-7ubuntu0.2USN-8704-1
Ubuntu:24.04:LTScpio2.15+dfsg-1ubuntu2.1USN-8704-1
Ubuntu:24.04:LTScpio2.15+dfsg-1ubuntu2.1UBUNTU-CVE-2026-66485
Ubuntu:26.04:LTScpio2.15+dfsg-2.1ubuntu0.1USN-8704-1
Ubuntu:26.04:LTScpio2.15+dfsg-2.1ubuntu0.1UBUNTU-CVE-2026-66485

Affected products (as reported)

VendorProductVersions
GNU cpio 0 – through 2.15

Weakness: CWE-789 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References