CVE-2026-110755: Text::CSV_XS versions before 1.65 for Perl allow quadratic CPU use by copying the unparsed remainder per record of CR-only input in getline

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-16 · updated 2026-10-20
Weakness: CWE-407

Description

Text::CSV_XS versions before 1.65 for Perl allow quadratic CPU use by copying the unparsed remainder per record of CR-only input in getline. With eol unset, the default, getline reads with Perl's default line separator, so input with CR-only line endings arrives as one chunk. After each record the parser copies the whole unparsed remainder into a new buffer, which the next call parses and copies again, so the work grows with the square of the input size. A reader with default options that is sent CSV with classic Mac line endings spends seconds of CPU time on a megabyte of input.

Affected products

Text-CSV_XS: before 1.65 — fixed in 1.65

How to fix

Upgrade to a fixed version: Text-CSV_XS 1.65. Check the vendor advisory for mitigations.

References

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