What’s Vulnerable › Vulnerabilities

CVE-2026-12844: List::SomeUtils::XS versions before 0.59 for Perl have a heap buffer overflow in the pairwise function

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-25 · updated 2026-10-25
• Weakness: CWE-122

Description

List::SomeUtils::XS versions before 0.59 for Perl have a heap buffer overflow in the pairwise function. pairwise() collects the values returned by the block into a heap buffer sized to the longer input array, then grows the buffer before each copy with a single quadrupling (alloc <<= 2) instead of a loop. A block call that returns more than four times the current allocation in one invocation outgrows that one quadrupling, and the copy writes past the end of the buffer. Any caller of pairwise() whose block returns, for a single pair, more than four times the longer input array's length writes past the buffer and corrupts the heap.

Affected products

• DROLSKY List::SomeUtils::XS: before 0.59 — fixed in 0.59

How to fix

Upgrade to a fixed version: DROLSKY List::SomeUtils::XS 0.59. Check the vendor advisory for mitigations.

References

• https://github.com/houseabsolute/List-SomeUtils-XS/commit/22549f78669b780d6aa338a2d2e49a3dedfffaa6.patch
• https://metacpan.org/release/DROLSKY/List-SomeUtils-XS-0.59/changes
• http://www.openwall.com/lists/oss-security/2026/06/25/11

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