CVE-2026-9538: \ — Fix

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0044

Probability of exploitation

0.35%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-789 CWE-789

Affected Products

Vendor	Product	Versions
archive\	\	< 3.10

References

Advisories & Patches

https://github.com/jib/archive-tar-new/commit/f9af01426038e29d9578825a0cd3626946ab08c7.patch

Other References

https://metacpan.org/release/BINGOS/Archive-Tar-3.10/changes http://www.openwall.com/lists/oss-security/2026/05/26/4

Frequently Asked Questions

What is CVE-2026-9538? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-9538? +

CVE-2026-9538 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0044, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-9538? +

CVE-2026-9538 affects products from archive\, specifically: \. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-9538? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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