CVE-2026-91971

Vikunja before 2.6.0 Denial of Service via Avatar Upload

Published Sep 15, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
Description
Vikunja before 2.6.0 fails to apply pixel decode limits to avatar and project-background upload endpoints, allowing authenticated users to upload crafted images that decode to excessive pixel counts. Attackers can upload small images with extreme aspect ratios that consume significant CPU and memory during processing, causing denial of service through repeated or concurrent uploads.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-4vh2-39rq-rq8j Vikunja: Unbounded image decode on avatar and project-background uploads enables decode/resize amplification
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Go-vikunja
Go-vikunja vikunja
Vendors & Products Go-vikunja
Go-vikunja vikunja
Type Values Removed Values Added
Description Vikunja before 2.6.0 fails to apply pixel decode limits to avatar and project-background upload endpoints, allowing authenticated users to upload crafted images that decode to excessive pixel counts. Attackers can upload small images with extreme aspect ratios that consume significant CPU and memory during processing, causing denial of service through repeated or concurrent uploads.
Title Vikunja before 2.6.0 Denial of Service via Avatar Upload
First Time appeared Vikunja
Vikunja vikunja
Weaknesses CWE-400
CPEs cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*
Vendors & Products Vikunja
Vikunja vikunja
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 21, 2026, 6:48 PM
Reserved
Sep 15, 2026, 11:09 AM
Status
Deferred
Published
Sep 15, 2026, 4:17 PM
Modified
Sep 21, 2026, 7:17 PM