How severe is CVE-2026-40103?

CVE-2026-40103 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-40103 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-40103?

CVE-2026-40103 affects Vikunja. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-40103?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-40103 have an EU (EUVD) identifier?

Yes. CVE-2026-40103 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21494.

When was CVE-2026-40103 published?

CVE-2026-40103 was published on 2026-04-10 and last updated on 2026-06-17.

CVE-2026-40103

CVE-2026-40103 is a medium-severity vulnerability in Vikunja with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-836.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (13th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21494
Weakness: CWE-836
Affected product: Vikunja
Published: 2026-04-10
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2026-40103?: 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.
How severe is CVE-2026-40103?: CVE-2026-40103 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-40103 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (13th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-40103?: CVE-2026-40103 affects Vikunja. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-40103?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40103 have an EU (EUVD) identifier?: Yes. CVE-2026-40103 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21494.
When was CVE-2026-40103 published?: CVE-2026-40103 was published on 2026-04-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*

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