Vulnerability · Published Mar 24, 2026 · Assigned by GitHub_M

CVE-2026-33678Vikunja has IDOR in Task Attachment ReadOne Allows Cross-Project File Access and Deletion

High 8.1

In plain English

A high-severity authorization bypass via user-controlled key in vikunja from go-vikunja. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.3%top 75.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, `TaskAttachment.ReadOne()` queries attachments by ID only (`WHERE id = ?`), ignoring the task ID from the URL path. The permission check in `CanRead()` validates access to the task specified in the URL, but `ReadOne()` loads a different attachment that may belong to a task in another project. This allows any authenticated user to download or delete any attachment in the system by providing their own accessible task ID with a target attachment ID. Attachment IDs are sequential integers, making enumeration trivial. Version 2.2.1 patches the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	code.vikunja.io/api	2.2.1	GHSA-jfmm-mjcp-8wq2
Go	code.vikunja.io/api	no fix listed	GO-2026-4853

Affected products (as reported)

Vendor	Product	Versions
go-vikunja	vikunja	< 2.2.1

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://github.com/go-vikunja/vikunja/security/advisories/GHSA-jfmm-mjcp-8wq2 x_refsource_CONFIRM
https://vikunja.io/changelog/vikunja-v2.2.2-was-released x_refsource_MISC