CVE-2026-35594
Published: 10 April 2026
Summary
CVE-2026-35594 is a medium-severity Insufficient Session Expiration (CWE-613) vulnerability in Vikunja Vikunja. Its CVSS base score is 6.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Valid Accounts (T1078); ranked at the 32.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21417
Vulnerability details
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's link share authentication (GetLinkShareFromClaims in pkg/models/link_sharing.go) constructs authorization objects entirely from JWT claims without any server-side database validation. When a project owner deletes a link share or downgrades…
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its permissions, all previously issued JWTs continue to grant the original permission level for up to 72 hours (the default service.jwtttl). This vulnerability is fixed in 2.3.0.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
JWTs from revoked/downgraded link shares remain usable, enabling continued access via valid authentication material.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Locks the device (typically after inactivity) until re-authentication, addressing insufficient session expiration by preventing indefinite access.
Automatically terminating sessions after a defined period directly enforces session expiration, preventing indefinite session lifetimes that attackers can exploit.
Re-authentication after inactivity or time-based triggers prevents indefinite use of potentially hijacked or stale sessions.
Terminating sessions and network connections upon completion prevents insufficient session expiration.
Directly enforces termination of network sessions after inactivity or end-of-session, preventing indefinite session lifetime.
Consistent clocks across systems allow session expiration and timeout enforcement to function as intended in distributed environments.
When the non-persistent artifact is a session or connection, mandatory termination implements the missing expiration that CWE-613 describes.
Timed refresh of session-related information or on-demand generation plus deletion implements proper session expiration.