High severity · published Aug 19, 2026
CVE-2026-76216
Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
Vikunja through 2.4.0 contains a principal-type confusion vulnerability where LinkSharing principals with id N are treated as user principals with users.id == N at three permission checks lacking type guards. Attackers with a link-share JWT can remove victims from teams, enumerate and delete victim bot users, or read team rosters by exploiting id collisions in the autoincrement space.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
VI
vikunja · go-vikunja
through 2.4.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-76216
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-76216
github.com
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-32r8-5843-4qw2
www.vulncheck.com
https://www.vulncheck.com/advisories/vikunja-through-principal-type-confusion-via-linksharing
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