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OpenAdvisories
Medium · 5.4 CVE-2026-42267 EUVD-2026-28506GHSA-3xc2-h5r3-wv3r

Kimai: Formula Injection via tag names in XLSX export

Published May 8, 2026 · Updated May 8, 2026 · Assigned by GitHub_M

Description

Kimai is an open-source time tracking application. From version 2.27.0 to before version 2.54.0, any ROLE_USER can create a tag with a formula string as its name (e.g. =SUM(54+51)) via POST /api/tags and assign it to a timesheet. When an admin exports timesheets to XLSX, ArrayFormatter.formatValue() joins tag names with implode() and returns the result unchanged. OpenSpout promotes any =-prefixed string to a FormulaCell, writing <f>SUM(54+51)</f> into the XLSX archive. Excel evaluates the formula when the file is opened. This issue has been patched in version 2.54.0.

Affected products

VendorProductAffectedFixed
kimai kimai >= 2.27.0, < 2.54.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
Packagist kimai/kimai >= 2.27.0, < 2.54.0 2.54.0 GHSA-3xc2-h5r3-wv3r

References