Heap corruption via undersized pairwise return buffer
Published Jun 25, 2026 · Updated Jun 25, 2026
Heap buffer overflow in List::SomeUtils::XS before 0.59 allows attackers to corrupt process memory through pairwise block output. The pairwise function sizes a heap buffer to the longer input array and performs only one fourfold allocation increase before copying every value returned by the block. The overwrite occurs when one block call returns more than four times the current allocation, corrupting the hosting Perl process heap.
Summary
What happened
Heap buffer overflow in List::SomeUtils::XS before 0.59 allows attackers to corrupt process memory through pairwise block output. The pairwise function sizes a heap buffer to the longer input array and performs only one fourfold allocation increase before copying every value returned by the block. The overwrite occurs when one block call returns more than four times the current allocation, corrupting the hosting Perl process heap.
The record
- CVE
- CVE-2026-12844
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- Dave Rolsky
- Product
- List::SomeUtils::XS
- Classifications
- CWE-787, CWE-122
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <0.59
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
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Your stack
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