Text::CSV_XS: Record splitting in CSV output via unquoted numeric-looking fields
Summary
Text::CSV_XS for Perl does not quote fields whose values were used as numbers and contain trailing newline or whitespace characters. An attacker who controls such a value can break the CSV record and inject extra rows or fields into exported files. Exploitation requires that untrusted data reaches a Perl application that writes CSV output.
Affected
- Text-CSV_XS versions before 1.65 (CPANSec: affected 0 to < 1.65)
Fixed in
- Text-CSV_XS 1.65 or later (released 2026-10-15)
Workaround
- No vendor workaround documented.
- Reject or strip CR and LF characters from fields before they are passed to combine or print.
- Quote all output fields, for example with the always_quote option (check module documentation).
Exploitation
- CISA SSVC: exploitation none, automatable yes, technical impact total.
- No public proof of concept confirmed at time of writing.
- Not recorded in the CISA KEV catalog according to a third-party aggregator; verify against CISA.
Our recommendation
- Upgrade Text-CSV_XS to version 1.65 or later in all Perl scripts, packages and applications.
- Check whether your Perl applications write CSV from user input, web forms, APIs or external data.
- Until patched, apply the input filtering or quoting workaround and process only trusted data.
- Verify distribution packages (Debian, Ubuntu, RHEL, SUSE, Fedora) against their advisories before assuming a fix is included.
- Monitor for vendor advisories and check downstream spreadsheet or import processes for tampered rows.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Fix commit (patch) github.com
- Text-CSV_XS 1.65 changes metacpan.org
- Text-CSV_XS 1.65 release metacpan.org
- VulDB vulnerability 421522 vuldb.com
- VulDB CVE record vuldb.com
- OSV Azure Linux entry osv.dev
- Ubuntu security status ubuntu.com
- Vulners NVD mirror vulners.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 30 Oct 2026, 17:36.
Original description (NVD)
Text::CSV_XS versions before 1.65 for Perl allow record splitting by writing strings used as numbers without quotes in combine. combine and print do not check whether a field needs quotes when its value has Perl's integer or numeric flag set. Perl sets these flags on a string used in a numeric operation when it parses as a number, which allows leading and trailing whitespace. With binary set, as csv does by default, "12\n" passes a check such as $qty > 0 and is then written unquoted with its newline. A value validated as a number can end the record early and turn the fields after it into a separate row.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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