go-vikunja up to 2.2.x link_sharing.go GetLinkShareFromClaims session expiration

Summaryinfo

A vulnerability was found in go-vikunja vikunja up to 2.2.x. It has been rated as critical. Impacted is the function GetLinkShareFromClaims of the file pkg/models/link_sharing.go. The manipulation leads to session expiration. This vulnerability is uniquely identified as CVE-2026-35594. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in go-vikunja vikunja up to 2.2.x. It has been rated as critical. This issue affects the function GetLinkShareFromClaims of the file pkg/models/link_sharing.go. The manipulation with an unknown input leads to a session expiration vulnerability. Using CWE to declare the problem leads to CWE-613. According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization." Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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 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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-35594 since 04/03/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 2.3.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 379d8a5c19334ffe4846003f590e202c31a75479 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• go-vikunja

Name

• vikunja

Version

• 2.0
• 2.1
• 2.2

License

• open-source

Website

• Product: https://github.com/go-vikunja/vikunja/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion