CVE-2026-107222: excelize Improper Validation of Array Index

Vulnerability summary

CVE-2026-107222 is a medium (CVSS 6.5) Improper Validation of Array Index vulnerability in excelize. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 07-10-2026
   PublishedVulnerability first disclosed.
2. 08-10-2026
   Last modifiedVulnerability information updated.

Description

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.7.0 to 2.11.0, conditional-format extraction indexes required child slices or dereferences an optional colorScale child without validating malformed rule structure. GetConditionalFormats reaches extractCondFmtCellIs and also indexes ColorScale.Cfvo, DataBar.Cfvo, and DataBar.Color without complete structural checks. When a crafted worksheet supplies a cellIs, dataBar, or colorScale rule missing expected children and the application calls GetConditionalFormats, missing formula, color, value-object, or colorScale data reaches an out-of-range index or nil dereference, allowing an attacker to panic and terminate an unprotected process. No fixed version is available as of this review.

• CWE-129Improper Validation of Array IndexThe product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
• CWE-476NULL Pointer DereferenceThe product dereferences a pointer that it expects to be valid but is NULL.