CVE-2026-40103: Vikunja is an open-source self-hosted task management platform

Q: How do I fix CVE-2026-40103?

vikunja: upgrade to 2.3.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-40103 being exploited?

CVE-2026-40103 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-40103 affect?

CVE-2026-40103 affects vikunja. Severity is medium (CVSS 4.3). Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's scoped API token enforcement for custom project background routes is method-confused. A token with only projects.background can successfully delete a

Q: How urgent is CVE-2026-40103?

Priority 23/100. Public exploit reference

Routine

MEDIUM 4.3UPGRADE

CVE-2026-40103 is a medium-severity flaw (CVSS 4.3) affecting vikunja. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's scoped API token enforcement for custom project background routes is method-confused. A token with only projects.background can successfully delete a project background, while a token with only projects.background_delete is rejected. This is a scoped-token authorization bypass. This vulnerability is fixed in 2.3.0.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.2% (top 87%)
CISA exploited list	No
Weakness	CWE-836
Published	2026-04-10
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-10 17:17 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

vikunja vikunja UPGRADE

Affected: < 2.3.0

Fixed in: 2.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 2.3.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade vikunja

Note

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

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-2026-40103?

vikunja: upgrade to 2.3.0. Exact commands for each OS are on this page.

Is CVE-2026-40103 being exploited?

CVE-2026-40103 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-2026-40103 affect?

CVE-2026-40103 affects vikunja. Severity is medium (CVSS 4.3). Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's scoped API token enforcement for custom project background routes is method-confused. A token with only projects.background can successfully delete a

How urgent is CVE-2026-40103?

Priority 23/100. Public exploit reference

Related CVEs

CVE-2026-35597 MEDIUM 5.9 UPGRADE Vikunja is an open-source self-hosted task management platform
CVE-2026-35596 MEDIUM 4.3 UPGRADE Vikunja is an open-source self-hosted task management platform
CVE-2026-35594 MEDIUM 6.5 UPGRADE Vikunja is an open-source self-hosted task management platform
CVE-2026-35595 HIGH 8.3 UPGRADE Vikunja is an open-source self-hosted task management platform
CVE-2026-35599 MEDIUM 6.5 UPGRADE Vikunja is an open-source self-hosted task management platform

References

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