---
id: "CVE-2026-110759"
kind: "vulnerability"
aliases: ["CVE-2026-110759"]
title: "Text::CSV_XS versions before 1.65 for Perl return a 0xFF byte that is not in the input for an empty last field\u2026"
severity: "critical"
cvss: 9.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["csv-import", "package", "perl", "text-csv-xs"]
not_affected_if: ["no-csv-parsing-of-crlf-input", "version-1.65-or-later"]
published_at: "2026-10-16T23:17:01+00:00"
first_seen_at: "2026-10-23T21:57:14+00:00"
updated_at: "2026-10-23T22:28:55+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-110759", "first_seen_at": "2026-10-23T21:57:14+00:00"}]
---

# Text::CSV_XS versions before 1.65 for Perl return a 0xFF byte that is not in the input for an empty last field…

Text::CSV_XS before 1.65 for Perl inserts a stray 0xFF byte into the last field when input ends with a separator and a lone CR. The application receives a byte that was not in its input, and UTF-8 flagged input yields malformed UTF-8.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

Check the installed Text::CSV_XS version and confirm it is below 1.65.

## Fix

Upgrade Text::CSV_XS to 1.65 or later.

## Timeline

- 2026-10-23T21:57:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-110759

## From the sources

Text::CSV_XS versions before 1.65 for Perl return a 0xFF byte that is not in the input for an empty last field followed by a lone CR in parse.

When the input to parse ends in a separator and a lone CR, the parser treats the end of the input as the next character and stores the end-of-file marker in the field as the byte 0xFF. With binary set, parse("a,\r") returns the fields "a" and "\xFF". On UTF-8 flagged input the last field is a UTF-8 flagged string holding that lone byte, which is malformed UTF-8. The same input with a non-empty last field is rejected as an error.

A CRLF file read line by line and chomped ends this way when its last column is empty, so the application receives a byte that is not in its input.

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