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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-107223: 0.37% estimated exploitation activity in the next 30 days; percentile 31.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The max attribute of a <col element in xl/worksheets/sheetN.xml is read verbatim on open with no check against MaxColumns, and flatCols() then walks Min..Max doing a deepcopy.Copy and append per iteration. Executed: max="300000", only about 18x past the real 16384 limit, cost 46.2 s of CPU and 122 MB on a single SetColWidth call, and the growth is linear in max up to 2^31-1. Confirmed at ae2113b (HEAD at the time of audit). Details col.go:547, flatCols(), with the two loops at :549 and :564: column.Min and column.Max are plain int attributes on xmlWorksheet.go:279-280, bound straight from the file. MaxColumns is 16384 (templates.go:176) and nothing in the parse path compares against it. The contrast that makes this an oversight rather than a design decision is inside the callers themselves. SetColWidth validates its own column argument through parseColRange, which clamps to MaxColumns. But flatCols iterates ws.Cols.Col, the file-loaded slice, so the caller's validated…

Published by the source

7 Oct 2026, 20:22 UTC

Last modified by the source

7 Oct 2026, 20:30 UTC

Source last checked

26 Oct 2026, 15:29 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-fq3v-74gv-27gm

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-fq3v-74gv-27gm

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# Patch Next advisory brief: CVE-2026-107223

Advisory: Excelize: Unbounded attribute is loaded with no MaxColumns check and expanded per-column by flatCols(), so any column mutator hangs or OOMs the process
IDs: CVE-2026-107223, GHSA-fq3v-74gv-27gm
Record: https://patchnext.com/advisories/cve-2026-107223 (revision 3, source checked 26 Oct 2026, 15:29 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/xuri/excelize/v2 2.11.1-0.20260807015645-a54c578af309. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/xuri/excelize/v2: affected >= 2.1.0, < 2.11.1-0.20260807015645-a54c578af309; fixed in 2.11.1-0.20260807015645-a54c578af309

## Suggested inspection (read-only)
- Go github.com/xuri/excelize/v2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/xuri/excelize/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-fq3v-74gv-27gm (OSV record GHSA-fq3v-74gv-27gm lists affected ranges: Go github.com/xuri/excelize/v2 >=2.1.0 <2.11.1-0.20260807015645-a54c578af309 (fixed))
- Verified: https://github.com/advisories/GHSA-fq3v-74gv-27gm (GitHub-reviewed advisory GHSA-fq3v-74gv-27gm lists affected ranges: Go github.com/xuri/excelize/v2 >=2.1.0 <2.11.1-0.20260807015645-a54c578af309)

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