Your RSA-2048 keys break in 2030. Find every one of them before attackers do.
🐹 Go
Not in CISA KEV

GHSA-f95f-77jx-fcjc — api

GHSA-f95f-77jx-fcjc is a CWE-639 vulnerability in code.vikunja.io/api. A fix is available for code.vikunja.io/api — see the affected versions and patch details below.

Vikunja has a Link Share Delete IDOR — Missing Project Ownership Check Allows Cross-Project Link Share Deletion

Also known asCVE-2026-33700GO-2026-4850
Published
Mar 25, 2026
Updated
Mar 26, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-f95f-77jx-fcjc.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs11th percentile — riskier than 11% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected
🐹code.vikunja.io/api

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

The DELETE /api/v1/projects/:project/shares/:share endpoint does not verify that the link share belongs to the project specified in the URL. An attacker with admin access to any project can delete link shares from other projects by providing their own project ID combined with the target share ID.

Details

The permission check in canDoLinkShare (pkg/models/link_sharing_permissions.go:53-70) validates admin access on the project from the :project URL parameter. However, the Delete method at pkg/models/link_sharing.go:305 queries only WHERE id = ? using the share ID, without verifying it belongs to the URL-specified project:

func (share *LinkSharing) Delete(s *xorm.Session, _ web.Auth) (err error) {
    _, err = s.Where("id = ?", share.ID).Delete(share)
    return
}

This is the same vulnerability class as GHSA-jfmm-mjcp-8wq2 (task attachment IDOR) and the fixed GHSA-mr3j-p26x-72x4 (task comment IDOR).

Additionally, ReadOne at line 203 has the same pattern (WHERE id = ? only), though it is not currently exploitable because CanRead fails first due to an unrelated issue with the hash parameter binding.

Impact

An authenticated user with admin access to any project can:

  • Delete link shares belonging to any other project in the system
  • Disrupt collaboration by removing shared access links
  • Link share IDs are sequential integers, making enumeration trivial

Reproduction

  1. User A creates Project A and a link share on it (share ID = X)
  2. User B creates Project B (gaining admin access)
  3. User B calls DELETE /api/v1/projects/{projectB_id}/shares/{X}
  4. The permission check passes (User B is admin on Project B)
  5. The delete executes WHERE id = X — deleting User A's link share

Recommended Fix

Change Delete at pkg/models/link_sharing.go:305 to:

_, err = s.Where("id = ? AND project_id = ?", share.ID, share.ProjectID).Delete(share)

Also fix ReadOne at line 203 as defense in depth.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gocode.vikunja.io/apiall versions2.2.1go get code.vikunja.io/api@v2.2.1

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for code.vikunja.io/api, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update code.vikunja.io/api to 2.2.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f95f-77jx-fcjc is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-f95f-77jx-fcjc can be triaged on real exposure rather than presence alone.

Tailored to GHSA-f95f-77jx-fcjc. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary The `DELETE /api/v1/projects/:project/shares/:share` endpoint does not verify that the link share belongs to the project specified in the URL. An attacker with admin access to any project can delete link shares from other projects by providing their own project ID combined with the target share ID. ## Details The permission check in `canDoLinkShare` (`pkg/models/link_sharing_permissions.go:53-70`) validates admin access on the project from the `:project` URL parameter. However, the `Delete` method at `pkg/models/link_sharing.go:305` queries only `WHERE id = ?` using the share ID,
O3 Security · Impact-Aware SCA

Is GHSA-f95f-77jx-fcjc in your dependencies?

O3 Security finds GHSA-f95f-77jx-fcjc across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works
GHSA-f95f-77jx-fcjc: api | O3 Security