What’s Vulnerable › Vulnerabilities

CVE-2026-9538: Archive::Tar versions before 3.10 for Perl allow memory exhaustion via attacker controlled entry size field in tar header

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-26 · updated 2026-07-23
• Weakness: CWE-789

Description

Archive::Tar versions before 3.10 for Perl allow memory exhaustion via attacker controlled entry size field in tar header. _read_tar() reads each entry's payload with $handle->read($$data, $block), where $block is derived from the entry's 12-byte size field in the tar header with no upper bound on that value. A crafted header declaring a multi-gigabyte size causes Perl to allocate a scalar of that size.

Affected products

• Archive::Tar Project Archive::Tar: before 3.10 — fixed in 3.10

How to fix

Upgrade to a fixed version: Archive::Tar Project Archive::Tar 3.10. Check the vendor advisory for mitigations.

References

• https://github.com/jib/archive-tar-new/commit/f9af01426038e29d9578825a0cd3626946ab08c7.patch
• https://metacpan.org/release/BINGOS/Archive-Tar-3.10/changes
• http://www.openwall.com/lists/oss-security/2026/05/26/4

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