CVE intelligence and bounded remediation

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

High CVSS 7.5

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.

Severity
High
CVSS
7.5 (3.1)
Published
2026-06-25
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-122, CWE-787

Affected products

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Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

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