CVE-2026-66485 is a vulnerability in GNU Cpio
Published on August 10, 2026
Uncontrolled Memory Allocation in GNU cpio
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
Vulnerability Analysis
CVE-2026-66485 can be exploited with local system access. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is a Stack Exhaustion Vulnerability?
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
CVE-2026-66485 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-66485
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Affected Versions
GNU cpio:- Before and including 2.15 is affected.