Excelize: Unbounded <col max> attribute is loaded with no MaxColumns check and expanded per-column by flatCols(), so any column mutator hangs or OOMs the process

[ Description ]Official description

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.1.0 to 2.11.0, flatCols expands file-loaded column ranges without validating Min and Max against the worksheet column limit. SetColWidth reaches flatCols, which expands xlsxCol.Min through xlsxCol.Max without enforcing MaxColumns. When a crafted worksheet supplies an oversized col max attribute and the application invokes a column mutator, flatCols performs a deep copy and append for every attacker-selected column number, allowing an attacker to consume excessive CPU and memory or trigger OOM. No fixed version is available as of this review.

[ Fixes ]Fixes and patches

• github.com/xuri/excelize/v2 2.11.1-0.20260807015645-a54c578af309Fixed version · GitHub Advisories · go package github.com/xuri/excelize/v2: upgrade to 2.11.1-0.20260807015645-a54c578af309 or later (affected >= 2.1.0, < 2.11.1-0.20260807015645-a54c578af309)
• Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
• Patch on github.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD

[ Packages ]Affected open-source packages

• github.com/xuri/excelize/v2 goAffected >= 2.1.0, < 2.11.1-0.20260807015645-a54c578af309 · fixed in 2.11.1-0.20260807015645-a54c578af309 · GHSA-fq3v-74gv-27gm

[ References ]References

• github.com/qax-os/excelize/commit/a54c578af309fa81f448143ed2b7a91192cc58a7Patch
• github.com/qax-os/excelize/pull/2370Issue TrackingPatch
• github.com/qax-os/excelize/security/advisories/GHSA-fq3v-74gv-27gmExploitVendor Advisory