Medium severity · published May 8, 2026
CVE-2026-42267
Kimai: Formula Injection via tag names in XLSX export
5.7
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 13% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KI
kimai · kimai
>= 2.27.0, < 2.54.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42267
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42267
Product
https://github.com/kimai/kimai/releases/tag/2.54.0
Exploit
https://github.com/kimai/kimai/security/advisories/GHSA-3xc2-h5r3-wv3r
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