CVE-2026-42267CWE-1236

Kimai: Formula Injection via tag names in XLSX export

Medium · published May 8, 2026

CVSS v4.0
5.4
EPSS
0%
Percentile
25.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
5.4 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
EPSS
0.00332 · 25.1th percentile
Weakness
CWE-1236 · Improper Neutralization of Formula Elements in a CSV File
Published
2026-05-08T03:28Z
EPSS history
Timeline
  • 08 MAY 03:28Z
    Kimai: Formula Injection via tag names in XLSX export
    cvelistv5