CVE-2026-56765 (GCVE-0-2026-56765)
Vulnerability from cvelistv5 – Published: 2026-07-10 13:57 – Updated: 2026-07-10 17:00
VLAI
EPSS
VEX
Title
Vikunja - Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR
Summary
Vikunja before 2.2.1 contains an authorization flaw where the LinkSharing.ReadAll endpoint exposes share hashes to users with read access, enabling permission escalation to admin-level shares. The GetTaskAttachment endpoint performs permission checks against user-supplied task IDs but fetches attachments by sequential ID without verifying ownership, allowing attackers to download and delete all file attachments across all projects instance-wide.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-10 16:40 UTC
CWE
- CWE-639 - Authorization Bypass Through User-Controlled Key
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/go-vikunja/vikunja/security/ad… | vendor-advisory |
| https://www.vulncheck.com/advisories/vikunja-unau… | third-party-advisory |
Impacted products
Date Public
2026-03-23 00:00
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