Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-91971— Vikunja before 2.6.0 Denial of Service via Avatar Upload

Quick assessment

Affected
go-vikunja vikunja
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Vikunja 在 2.6.0 版本之前未能对头像和项目背景上传端点实施像素解码限制，使得经过身份验证的用户可以上传经过恶意构造的图像，这些图像在解码后会生成过高的像素数量。攻击者可以上传具有极端宽高比的小尺寸图像，在图像处理过程中消耗大量 CPU 和内存资源，通过重复或并发上传导致服务拒绝（DoS）攻击。

CVSS 6.5 · Medium
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-91971

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Vikunja before 2.6.0 Denial of Service via Avatar Upload
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
未加控制的资源消耗(资源穷尽)
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
go-vikunja vikunja 0 ~ 2.6.0 -

II. Public POCs for CVE-2026-91971

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-91971

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-91971 (2)

Same Patch Batch · go-vikunja · 2026-09-15 · 13 CVEs total

CVE-2026-91972 7.5 HIGH Vikunja before 2.6.0 Authentication Bypass via Unthrottled API
CVE-2026-91985 7.5 HIGH Vikunja before 2.6.0 Privilege Escalation via Link Share Hash
CVE-2026-91973 7.5 HIGH Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuth
CVE-2026-91968 6.5 MEDIUM vikunja before 2.6.0 Denial of Service via unbounded filter recursion
CVE-2026-91979 6.5 MEDIUM Vikunja before 2.6.0 Denial of Service via Decompression Bomb
CVE-2026-91970 6.5 MEDIUM Vikunja before 2.6.0 Resource Exhaustion via Planka Migration
CVE-2026-91969 6.5 MEDIUM vikunja before 2.6.0 Resource Exhaustion via CSV Migration
CVE-2026-91982 4.3 MEDIUM Vikunja before 2.6.0 TOTP Secret Disclosure via API
CVE-2026-91980 4.3 MEDIUM vikunja before 2.6.0 Team Enumeration via Project Share
CVE-2026-91981 4.3 MEDIUM Vikunja before 2.6.0 User Enumeration via v2 API
CVE-2026-91983 4.3 MEDIUM Vikunja before 2.6.0 API Token Scope Bypass via expand Parameter
CVE-2026-91984 4.3 MEDIUM Vikunja before 2.6.0 Broken Object-Level Authorization via task-position

IV. Related Vulnerabilities

Same product: vikunja
Same vendor: go-vikunja
Same weakness: CWE-400

V. Comments for CVE-2026-91971

No comments yet

Leave a comment