CVE-2026-66485

Uncontrolled Memory Allocation in GNU cpio

Published Aug 10, 2026 CVSS 4.0 · 4.6 Medium EPSS < 1% KEV · Not listed
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

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8704-1 GNU cpio vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-120
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.0, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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
Title Uncontrolled Memory Allocation in GNU cpio
First Time appeared Gnu
Gnu cpio
Weaknesses CWE-789
CPEs cpe:2.3:a:gnu:cpio:*:*:*:*:*:*:*:*
Vendors & Products Gnu
Gnu cpio
References
Metrics cvssV4_0

{'score': 4.6, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
CERT-PL
Published
Updated
Aug 10, 2026, 10:56 AM
Reserved
Jul 27, 2026, 11:32 AM
Status
Deferred
Published
Aug 10, 2026, 11:17 AM
Modified
Oct 24, 2026, 4:10 PM
Severity
Moderate
Public date
Aug 10, 2026, 10:25 AM