What’s Vulnerable › Vulnerabilities

CVE-2026-17591: Libarchive: libarchive: use-after-free via aliased mac metadata copy

• Severity: low (CVSS 3.6 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-16 · updated 2026-10-19
• Weakness: CWE-416

Description

A flaw was found in libarchive. An attacker can cause a Denial of Service (DoS) or potential information disclosure due to a use-after-free vulnerability, which occurs when a program reads memory that has already been released. This issue arises when the archive_entry_copy_mac_metadata() function deallocates an internal buffer before completing a data copy. An attacker who can supply input to an application utilizing this function can trigger the flaw to crash the application or read uninitialized memory data.

Affected products

• Red Hat Enterprise Linux 10: all versions
• Red Hat Enterprise Linux 6: all versions
• Red Hat Enterprise Linux 7: all versions
• Red Hat Enterprise Linux 8: all versions
• Red Hat Enterprise Linux 9: all versions
• Red Hat Hardened Images: all versions — fixed in 3.8.9-2.1.hum1

How to fix

Upgrade to a fixed version: Red Hat Hardened Images 3.8.9-2.1.hum1. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:77775
• https://access.redhat.com/security/cve/CVE-2026-17591
• https://bugzilla.redhat.com/show_bug.cgi?id=2554209
• https://github.com/libarchive/libarchive/pull/3318

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