GHSA-564F-WX8X-878H
Vulnerability from github – Published: 2026-03-20 17:25 – Updated: 2026-03-20 17:25Summary
The DELETE /api/v1/projects/:project/background endpoint checks CanRead permission instead of CanUpdate, allowing any user with read-only access to a project to permanently delete its background image.
Details
The RemoveProjectBackground handler (pkg/modules/background/handler/background.go) reuses checkProjectBackgroundRights, a helper originally written for the read-only GetProjectBackground endpoint. This helper only verifies CanRead permission. In contrast, the handler for setting a background (setBackgroundPreparations) correctly checks CanUpdate.
As a result, destructive write operations (deleting the background file from storage and clearing the project's background_file_id and background_blur_hash fields) are gated behind a read-only permission check.
Impact
A user with read-only access to a project — via direct sharing, team membership, link share tokens with read permission, or read-scoped API tokens — can permanently delete the project's background image. The background file is removed from storage and cannot be recovered. This constitutes unauthorized data destruction.
Reproduction
- User A creates a project and sets a background image.
- User A shares the project with User B with read-only permission.
- User B sends:
DELETE /api/v1/projects/{project_id}/backgroundwith a valid auth token. - The request succeeds. The background image is permanently deleted.
References
pkg/modules/background/handler/background.go—RemoveProjectBackground(line 416),checkProjectBackgroundRights(line 304),setBackgroundPreparations(line 106)pkg/routes/routes.goline 665 — route registration
Credits
This vulnerability was found using GitHub Security Lab Taskflows.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "code.vikunja.io/api"
},
"ranges": [
{
"events": [
{
"introduced": "0.20.2"
},
{
"fixed": "2.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-33312"
],
"database_specific": {
"cwe_ids": [
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-20T17:25:21Z",
"nvd_published_at": "2026-03-20T15:16:18Z",
"severity": "MODERATE"
},
"details": "## Summary\n\nThe `DELETE /api/v1/projects/:project/background` endpoint checks `CanRead` permission instead of `CanUpdate`, allowing any user with read-only access to a project to permanently delete its background image.\n\n## Details\n\nThe `RemoveProjectBackground` handler (`pkg/modules/background/handler/background.go`) reuses `checkProjectBackgroundRights`, a helper originally written for the read-only `GetProjectBackground` endpoint. This helper only verifies `CanRead` permission. In contrast, the handler for *setting* a background (`setBackgroundPreparations`) correctly checks `CanUpdate`.\n\nAs a result, destructive write operations (deleting the background file from storage and clearing the project\u0027s `background_file_id` and `background_blur_hash` fields) are gated behind a read-only permission check.\n\n## Impact\n\nA user with read-only access to a project \u2014 via direct sharing, team membership, link share tokens with read permission, or read-scoped API tokens \u2014 can permanently delete the project\u0027s background image. The background file is removed from storage and cannot be recovered. This constitutes unauthorized data destruction.\n\n## Reproduction\n\n1. User A creates a project and sets a background image.\n2. User A shares the project with User B with **read-only** permission.\n3. User B sends: `DELETE /api/v1/projects/{project_id}/background` with a valid auth token.\n4. The request succeeds. The background image is permanently deleted.\n\n## References\n\n- `pkg/modules/background/handler/background.go` \u2014 `RemoveProjectBackground` (line 416), `checkProjectBackgroundRights` (line 304), `setBackgroundPreparations` (line 106)\n- `pkg/routes/routes.go` line 665 \u2014 route registration\n\n## Credits\n\nThis vulnerability was found using [GitHub Security Lab Taskflows](https://github.com/GitHubSecurityLab/seclab-taskflows).",
"id": "GHSA-564f-wx8x-878h",
"modified": "2026-03-20T17:25:21Z",
"published": "2026-03-20T17:25:21Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-564f-wx8x-878h"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33312"
},
{
"type": "PACKAGE",
"url": "https://github.com/go-vikunja/vikunja"
},
{
"type": "WEB",
"url": "https://vikunja.io/changelog/vikunja-v2.2.0-was-released"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Vikunja read-only users can delete project background images via broken object-level authorization"
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.