CVE-2026-123523: DoS (CVSS 6.5)

Description

Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated users to exhaust server memory by requesting avatars at many distinct sizes. Attackers can upload a noisy avatar and fetch it at each size up to 1024, caching roughly a gigabyte per account without eviction and causing the API process to be OOM-killed.

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CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0031

Probability of exploitation

0.24%

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-770 CWE-770

References

Other References

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-3x3m-2j93-w46j https://www.vulncheck.com/advisories/vikunja-before-2.7.1-memory-exhaustion-via-unbounded-avatar-size-cache https://github.com/go-vikunja/vikunja/security/advisories/GHSA-3x3m-2j93-w46j

Frequently Asked Questions

What is CVE-2026-123523? +

Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated users to exhaust server memory by requesting avatars at many distinct sizes. Attackers can upload a noisy avatar and fetch it at each size up to 1024, caching roughly a gigabyte per account without eviction and causing the API process to be OOM-killed. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-123523? +

CVE-2026-123523 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0031, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-123523? +

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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