Published May 26, 2026Sources checked Oct 28, 2026
7.5HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-9538 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.5%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
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.