CVE-2026-123518

MEDIUM
Published Nov 8, 2026 Modified Nov 9, 2026 CWE-639

Description

Vikunja before 2.7.1 contains an incorrect authorization vulnerability in TaskBucket.CanUpdate, which checks write access to the bucket's project and to the task separately but never verifies that both belong to the same project. Authenticated users with write access to two projects can move a task into another project's kanban bucket. This persists cross-project task_buckets rows that count toward bucket limits and, for done buckets, toggle the task's done state.

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CVSS v3.1 Score

4.3
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

EPSS — Exploit Prediction

0.0019
Probability of exploitation
0.09%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-639 CWE-639

References

Frequently Asked Questions

What is CVE-2026-123518? +
Vikunja before 2.7.1 contains an incorrect authorization vulnerability in TaskBucket.CanUpdate, which checks write access to the bucket's project and to the task separately but never verifies that both belong to the same project. Authenticated users with write access to two projects can move a task into another project's kanban bucket. This persists cross-project task_buckets rows that count toward bucket limits and, for done buckets, toggle the task's done state. It has a CVSS v3.1 base score of 4.3 (MEDIUM).
How severe is CVE-2026-123518? +
CVE-2026-123518 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-123518? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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