CVE-2026-91971: Uncontrolled Resource Consumption in go-vikunja vikunja
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.
AI Analysis
Technical Summary
Vikunja versions prior to 2.6.0 do not enforce pixel decode limits on avatar and project-background image upload endpoints. Authenticated attackers can exploit this by uploading small images with extreme aspect ratios that, when decoded, consume excessive CPU and memory resources. This leads to denial of service conditions through repeated or concurrent uploads. The vulnerability is identified as CVE-2026-91971 with a CVSS 4.0 base score of 7.1, indicating high severity.
Potential Impact
Successful exploitation results in denial of service due to excessive CPU and memory consumption on the server handling image uploads. This can degrade service availability for legitimate users. There is no indication of privilege escalation, data disclosure, or code execution from the provided data.
Mitigation Recommendations
A fix is available in Vikunja version 2.6.0 and later. Users should upgrade to version 2.6.0 or above to mitigate this vulnerability. No additional mitigation guidance is provided or required based on the vendor advisory data.
CVE-2026-91971: Uncontrolled Resource Consumption in go-vikunja vikunja
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.
CVSS v4.0
Score 7.1high
Affected software
go-vikunja
vikunja
pkg:golang/github.com/go-vikunja/vikunjaRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Vikunja versions prior to 2.6.0 do not enforce pixel decode limits on avatar and project-background image upload endpoints. Authenticated attackers can exploit this by uploading small images with extreme aspect ratios that, when decoded, consume excessive CPU and memory resources. This leads to denial of service conditions through repeated or concurrent uploads. The vulnerability is identified as CVE-2026-91971 with a CVSS 4.0 base score of 7.1, indicating high severity.
Potential Impact
Successful exploitation results in denial of service due to excessive CPU and memory consumption on the server handling image uploads. This can degrade service availability for legitimate users. There is no indication of privilege escalation, data disclosure, or code execution from the provided data.
Mitigation Recommendations
A fix is available in Vikunja version 2.6.0 and later. Users should upgrade to version 2.6.0 or above to mitigate this vulnerability. No additional mitigation guidance is provided or required based on the vendor advisory data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-15T11:09:54.873Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa9651c55bf5e2cf502eb24
Added to database: 09/15/2026, 15:32:44 UTC
Last enriched: 09/15/2026, 15:47:37 UTC
Last updated: 09/16/2026, 02:32:28 UTC
Views: 10
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