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USN-8704-1: GNU cpio vulnerabilities

USN-8704-1: GNU cpio vulnerabilities

Ubuntu • August 31, 2026

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...

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...

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 )

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 )

In general, a standard system update will make all the necessary changes.

The problem can be corrected by updating your system to the following package versions:

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Extracted Entities

Attack Types (1)

CWE Weaknesses (1)

Platforms (1)