CVE-2026-76216
Vikunja through 2.4.0 Principal-Type Confusion via LinkSharing
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.
INFO
Published Date :
Aug. 19, 2026, 2:17 p.m.
Last Modified :
Aug. 20, 2026, 5:19 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Vikunja to version 2.4.1 or later.
- Review and enforce type guards in permission checks.
- Validate principal IDs rigorously in access control.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-76216.
| URL | Resource |
|---|---|
| https://github.com/go-vikunja/vikunja/security/advisories/GHSA-32r8-5843-4qw2 | |
| https://www.vulncheck.com/advisories/vikunja-through-principal-type-confusion-via-linksharing |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-76216 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-76216
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-76216 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-76216 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 20, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-76216', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-20T16:10:21.585796Z'} -
New CVE Received by [email protected]
Aug. 19, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'go-vikunja', 'product': 'vikunja', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.4.0'}], 'packageURL': 'pkg:golang/code.vikunja.io/api', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/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 Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-639 Added Reference https://github.com/go-vikunja/vikunja/security/advisories/GHSA-32r8-5843-4qw2 Added Reference https://www.vulncheck.com/advisories/vikunja-through-principal-type-confusion-via-linksharing