Medium severity · published Aug 10, 2026
CVE-2026-66485
Uncontrolled Memory Allocation in GNU cpio
4.6
CVSS
0.2%
EPSS
No
On KEV
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
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 8% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CP
cpio · GNU
through 2.15 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66485
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-66485
cert.pl
https://cert.pl/en/posts/2026/08/CVE-2026-66484
git.savannah.gnu.org
https://git.savannah.gnu.org/cgit/cpio.git
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