Summary
It was discovered that cpio incorrectly sanitized hard-link targets when
extracting tar archives in copy-in mode. If a user or automated system
were tricked into extracting a specially crafted tar archive, an attacker
could possibly use this issue to create hard links to files outside the
extraction directory, even when using the --no-absolute-filenames option.
(CVE-2026-66484)
It was discovered that cpio did not properly bound the stack memory
allocated for pathnames during archive extraction. If a user or automated
system were tricked into extracting a specially crafted cpio archive, an
attacker could possibly use this issue to cause cpio to crash, resulting
in a denial of service. (CVE-2026-66485)
It was discovered that cpio did not properly escape archive member names
when listing archive contents. If a user or automated system were tricked
into listing a specially crafted archive, an attacker could possibly use
this issue to inject misleading output or malicious terminal control
sequences. (CVE-2026-66486)
Fixed packages 7
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 22.04 LTS 22.04:LTS | cpio | 2.13+dfsg-7ubuntu0.2 |
| Ubuntu · 24.04 LTS 24.04:LTS | cpio | 2.15+dfsg-1ubuntu2.1 |
| Ubuntu · 26.04 LTS 26.04:LTS | cpio | 2.15+dfsg-2.1ubuntu0.1 |
| Ubuntu · Pro 14.04 LTS Pro:14.04:LTS | cpio | 2.11+dfsg-1ubuntu1.2+esm3 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | cpio | 2.11+dfsg-5ubuntu1.1+esm2 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | cpio | 2.12+dfsg-6ubuntu0.18.04.4+esm1 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | cpio | 2.13+dfsg-2ubuntu0.4+esm1 |
Vulnerabilities 3
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Medium 4.6
Path Traversal in GNU cpio
GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed t…
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Medium 4.6
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. …
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Medium 4.6
Improper Output Encoding in GNU cpio
GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio arc…