Cyber Resilience

CVE-2026-42267

Kimai 2.27.0 – 2.54.0

Public PoC
Published
08 May 2026
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v4 5.4
Click a component to see what it means
Raw vectorCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0022 13th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-42267 is a medium-severity Improper Neutralization of Formula Elements in a CSV File (CWE-1236) vulnerability in Kimai Kimai. Its CVSS base score is 5.4 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique User Execution (T1204); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-15 (Information Output Filtering) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)
CWE-1236

Related Threats

MITRE ATT&CK Enterprise Techniques

T1204 User Execution Execution
An adversary may rely upon specific actions by a user in order to gain execution.
attack.mitre.org →
T1204.002 Malicious File Execution
An adversary may rely upon a user opening a malicious file in order to gain execution.
attack.mitre.org →
T1566 Phishing Initial Access
Adversaries may send phishing messages to gain access to victim systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-44298Same product: Kimai Kimai
CVE-2026-23626Same product: Kimai Kimai
CVE-2024-29200Same product: Kimai Kimai
CVE-2026-40479Same product: Kimai Kimai
CVE-2023-53957Same product: Kimai Kimai
CVE-2023-46245Same product: Kimai Kimai
CVE-2026-40486Same product: Kimai Kimai
CVE-2026-41498Same product: Kimai Kimai
CVE-2024-4596Same product: Kimai Kimai
CVE-2026-28685Same product: Kimai Kimai

Affected Assets

kimai
kimai
2.27.0 — 2.54.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.10

Mitigating Controls (NIST 800-53 r5) AI

SI-15 Information Output Filtering good match

Output filtering/validation directly stops unneutralized formula elements from being written into CSV files.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require output neutralization for untrusted CSV content to block formula injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect formula injection but does not itself implement the mitigation.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and output encoding that directly prevents formula injection in CSV exports.

A.8.26 Application security requirements partial match
prevents

Application security requirements include rules for safe CSV generation and handling of untrusted data.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles encourage safe data export design but do not specifically address CSV formula neutralization.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly require neutralization of special characters when writing CSV files.

References