CVE-2026-42267: Kimai is an open-source time tracking application

Routine

MEDIUM 5.7UPGRADE

CVE-2026-42267 is a medium-severity flaw (CVSS 5.7) affecting kimai. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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>

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.7 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.2% (top 88%)
CISA exploited list	No
Weakness	CWE-1236
Published	2026-05-08
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: kimai

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-08 04:16 UTCPublished CVE record published
2026-06-17 10:47 UTCUpdated Record last modified

kimai kimai UPGRADE

Affected: >= 2.27.0 and < 2.54.0

Fixed in: 2.54.0

Safe to downgrade to: a release before 2.27.0

1. Check installed version

apt-cache policy kimai || rpm -q kimai || kimai --version

2. UPGRADE to 2.54.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade kimai

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade kimai

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.27.0 (Debian / Ubuntu)

apt-cache madison kimai sudo apt install kimai=<VERSION_BEFORE_2.27.0> sudo apt-mark hold kimai

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list kimai sudo dnf downgrade kimai-<VERSION_BEFORE_2.27.0> sudo dnf versionlock add kimai

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42267?

kimai: upgrade to 2.54.0. Exact commands for each OS are on this page.

Is CVE-2026-42267 being exploited?

CVE-2026-42267 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42267 affect?

CVE-2026-42267 affects kimai. Severity is medium (CVSS 5.7). 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 ad

How urgent is CVE-2026-42267?

Priority 28/100. Public exploit reference

Related CVEs

CVE-2026-44298 MEDIUM 4.1 UPGRADE Kimai is an open-source time tracking application
CVE-2026-41498 LOW 3.3 UPGRADE Kimai is an open-source time tracking application

References

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