EUVD-2026-78656Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Primary rating from Vendor (VulnCheck) · only source for this CVE.
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
3DescriptionCVE.org
Vikunja before 2.6.0 fails to properly restrict access to the link-share hash field in single-share read endpoints, allowing read-only members to obtain the share's secret credential. Attackers can exchange the disclosed hash for a link-share JWT at the share's permission level to escalate privileges and perform unauthorized writes or administrative actions.
AnalysisAI
Vikunja prior to 2.6.0 leaks the secret hash that backs a project's link shares through its single-share read endpoint, so any authenticated user holding only read-only membership in a project can read the credential that is supposed to be reserved for the link itself. Because that hash can be exchanged for a link-share JWT carrying the share's own permission level, the disclosure becomes a privilege-escalation primitive: if the leaked share was created with write or admin rights, the attacker inherits them and can modify tasks, projects, or administrative settings. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Recommended ActionAI
Within 24 hours, inventory all Vikunja instances and identify those running any version below 2.6.0, then treat them as exposed until upgraded; simultaneously enumerate existing project link shares and revoke or regenerate any created with write or admin permissions, since those credentials may already be recoverable by read-only members. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
Weak password policy in Vikunja task management before 2.0.0 allows users to set trivially guessable passwords. PoC avai
Stored cross-site scripting (XSS) in Vikunja prior to version 2.0.0 allows authenticated attackers to steal authenticati
Vikunja before version 2.0.0 contains a path traversal vulnerability in its backup restoration function that fails to va
Vikunja is an open-source self-hosted task management platform. [CVSS 6.1 MEDIUM]
Business logic vulnerability in Vikunja task management platform before 2.1.0 allows incomplete resource cleanup, potent
Cross-tenant information disclosure in the self-hosted task manager Vikunja (0.24.0 through 2.3.0) lets a holder of any
Instance-wide data breach in Vikunja before 2.2.1 lets remote attackers exfiltrate and destroy every file attachment acr
Vikunja instances before 2.6.0 expose CalDAV BasicAuth endpoints (/dav, /.well-known, and /feeds) that are not covered b
Vikunja versions before 2.6.0 ship authentication endpoints under /api/v2 (login, register, password-reset, and OAuth to
Principal type confusion in Vikunja (versions 0.22.0-2.3.0) allows an authenticated low-privilege attacker to fully cont
Vikunja, an open-source self-hosted task management platform, contains an insecure direct object reference (IDOR) vulner
Principal-type confusion in Vikunja through 2.4.0 allows an attacker holding a valid link-share JWT to impersonate arbit
Same weakness CWE-200 – Information Exposure
View allSame technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today