CVE-2026-56765
CRITICALVikunja < 2.2.1 - Link Share Disclosure and Attachment IDOR
Title source: manualDescription
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.
References (2)
Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-2pv8-4c52-mf8j)
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-2pv8-4c52-mf8j
Third Party Advisory third-party-advisory
VulnCheck Advisory: Vikunja - Unauthenticated Instance-Wide Data Breach via Link Share Hash Disclosure Chained with Cross-Project Attachment IDOR
https://www.vulncheck.com/advisories/vikunja-unauthenticated-instance-wide-data-breach-via-link-share-hash-disclosure-chained-with-cross-project-attachment-idor
Scores
CVSS v3
9.8
EPSS
0.0036
EPSS Percentile
28.5%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
total
Details
CWE
CWE-639
Status
published
Products (2)
Vikunja/Vikunja
< 2.2.1
Vikunja/Vikunja
2.2.1
Published
Jul 10, 2026
Tracked Since
Jul 10, 2026