Vikunja: Write-level project members can delete admin-tier link shares through an unloaded permission check

Summary A project member with Write permission can delete an admin-tier link share on that project. The deletion authorization check reads the permission from an object populated only with URL IDs, rather than from the stored share. Its zero value is Read, so the check falls through to project...

EUVD-2026-78652

Vikunja: Link-share token can enumerate users through the v2 API...

Vikunja: Link-share token can enumerate users through the v2 API

Summary A link-share token, the credential you hand out to let someone view a shared project, can call the v2 user-search endpoints, which it was never meant to reach. The v1 versions of the same endpoints correctly reject link-share tokens; the v2 versions don't. As a result, anyone with a share...

EUVD-2026-78656

Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint v1 and v2 and escalate to the share's permission level...

Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint (v1 and v2) and escalate to the share's permission level

Summary A user who has only read permission on a project can call the single link-share read endpoint and receive the share's hash field — the secret credential that the anonymous POST /shares/share/auth endpoint exchanges for a link-share JWT carrying the share's permission read / read-write /...

EUVD-2026-51991

Vikunja: Link-share principal ID collision allows cross-account API token issuance and management...

Vikunja: Link-share principal ID collision allows cross-account API token issuance and management

Executive Summary Vikunja accepts both regular-user JSON Web Tokens JWTs and link-share JWTs through its generic authenticated API route group. A link-share JWT resolves to a models.LinkSharing principal whose GetID method returns the numeric linkshares.id. The API-token management model then...

Duplicate Advisory: Vikunja: Read-only project members can obtain any link share's access hash via the single-share read endpoint (v1 and v2) and escalate to the share's permission level

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-qfwc-vx6f-3g6g. This link is maintained to preserve external references. Original Description Vikunja before 2.6.0 fails to properly restrict access to the link-share hash field in single-share read endpoints,...

Duplicate Advisory: Vikunja: Link-share token can enumerate users through the v2 API

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-vfxw-3x8p-2vjr. This link is maintained to preserve external references. Original Description Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints...

CVE-2026-91985

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...

CVE-2026-91981

Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint...

CVE-2026-91985 Vikunja before 2.6.0 Privilege Escalation via Link Share Hash

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...

CVE-2026-91985

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...

CVE-2026-91985 Vikunja before 2.6.0 Privilege Escalation via Link Share Hash

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...

CVE-2026-91985

Vikunja before 2.6.0 contains an access-control flaw in its single-share read endpoints: the link-share hash field is not properly restricted, allowing read-only members to obtain the share's secret credential. An attacker can then exchange that hash for a link-share JWT at the share's permission...

CVE-2026-91985 Vikunja before 2.6.0 Privilege Escalation via Link Share Hash

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...

CVE-2026-91981

Vikunja , a self-hosted task management application, is affected by a user enumeration vulnerability in versions before 2.6.0 . The root cause is improper validation of link-share tokens in the v2 API user search endpoints. An attacker holding a read-only share link can enumerate project members ...

CVE-2026-91981 Vikunja before 2.6.0 User Enumeration via v2 API

Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint...

CVE-2026-91981

Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint...

PT-2026-92095

Name of the Vulnerable Software and Affected Versions Vikunja versions prior to 2.6.0 Description Improper validation of link-share tokens in the v2 API user search endpoints allows attackers possessing a read-only share link to enumerate project users through the 'projects' endpoint and verify t...