Is CVE-2026-115943 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-115943 being exploited in the wild.

How severe is CVE-2026-115943?

Informational severity, published 29 October 2026.

Which products and versions are affected?

CPAN Spreadsheet::XLSX before 0.19.

Is there a fix for CVE-2026-115943?

Yes: fixed in 0.19. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-115943 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-115943?

Check whether you run CPAN Spreadsheet::XLSX at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-115943: Spreadsheet::XLSX remote code execution via format condition eval

CVE-2026-115943 · Severity: info · Published 2026-10-29

Spreadsheet::XLSX is a Perl library that reads Excel spreadsheet files. Versions before 0.19 contain a code execution vulnerability in how they process number format conditions from XLSX files. An attacker can craft a malicious spreadsheet that executes arbitrary Perl code when the file is parsed, potentially compromising any system that processes untrusted XLSX files with this library.

Vendors: CPAN.

Quick answers

Is CVE-2026-115943 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-115943 being exploited in the wild.
How severe is CVE-2026-115943?: Informational severity, published 29 October 2026.
Which products and versions are affected?: CPAN Spreadsheet::XLSX before 0.19.
Is there a fix for CVE-2026-115943?: Yes: fixed in 0.19. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-115943 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-115943?: Check whether you run CPAN Spreadsheet::XLSX at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 0.19

Technical details

The vulnerability exists in the ExcelFmt component, which uses string eval() to evaluate number format conditions (e.g., [>100]) extracted directly from the XLSX file without sanitization. An attacker can inject arbitrary Perl code into a format condition string, which executes during Spreadsheet::XLSX->new() parsing. The fix in version 0.19 replaces the string eval with strict numeric comparisons, eliminating code execution.

Affected products

CPAN Spreadsheet::XLSX before 0.19

Timeline

2026-10-29: disclosed
2026-10-29: patched

References

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