CVE-2026-110759 HMBRAND CVE debrief

Who should care

Defenders responsible for Perl applications using Text::CSV_XS should assess exposure and prioritize verification and potential upgrades. This includes reviewing application code to ensure proper handling of CSV input and monitoring for potential exploitation attempts. Additionally, defenders should verify the version of Text::CSV_XS in use and upgrade to version 1.65 or later if necessary.

Why it matters

CVE-2026-110759 is a vulnerability in Text::CSV_XS versions before 1.65 for Perl that can result in a malformed UTF-8 string being returned. Defenders responsible for Perl applications using Text::CSV_XS should assess exposure and prioritize verification and potential upgrades.

• Defenders should verify the version of Text::CSV_XS in use and upgrade to version 1.65 or later if necessary to prevent potential issues with malformed UTF-8 strings.
• Review application code to ensure proper handling of CSV input to prevent potential issues.
• Monitor for potential exploitation attempts to detect potential attacks.

Technical summary

The vulnerability occurs when the input to parse ends in a separator and a lone CR, causing the parser to treat the end of the input as the next character and store the end-of-file marker in the field as the byte 0xFF. This can result in a malformed UTF-8 string being returned. The issue affects Text::CSV_XS versions before 1.65 for Perl. Defenders should prioritize verifying the version of Text::CSV_XS in use and upgrading to version 1.65 or later if necessary. The vulnerability can be triggered when a CRLF file is read line by line and chomped, ending with an empty last field.

Defensive priority

Defenders should prioritize verifying the version of Text::CSV_XS in use and upgrading to version 1.65 or later if necessary.

Recommended defensive actions

• Verify the version of Text::CSV_XS in use and upgrade to version 1.65 or later if necessary.
• Review application code to ensure proper handling of CSV input.
• Monitor for potential exploitation attempts.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability was reported by an unknown source and is described in the CVE record and NVD vulnerability detail page. The issue arises when the input to parse ends in a separator and a lone CR, causing the parser to treat the end of the input as the next character and store the end-of-file marker in the field as the byte 0xFF. This can result in a malformed UTF-8 string being returned. Defenders should verify the version of Text::CSV_XS in use and review application code to ensure proper handling of CSV input.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.