GHSA-vcgv-7rvm-m3vp: Duplicate Advisory Vikunja: Link-share Token Can Enumerate Vulnerability

MODERATE
Share
CVSS 4.3
CWE-200
Published
Advisory Summary

GHSA-vcgv-7rvm-m3vp is a MODERATE (CVSS 4.3) vikunja: link-share token can enumerate vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Duplicate Advisory libraries in the Go ecosystem. The issue involves vikunja: link-share token can enumerate users through the v2 api. Remediation is available in the latest vendor maintenance releases.

GHSA-vcgv-7rvm-m3vp at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-vcgv-7rvm-m3vp
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Duplicate Advisory
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix GHSA-vcgv-7rvm-m3vp

To remediate this vulnerability, upgrade all affected Duplicate Advisory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

code.vikunja.io/api fixed: Latest secure release 
Upgrade code.vikunja.io/api to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for code.vikunja.io/api

How to Check if You Are Affected

To determine whether your application is affected by GHSA-vcgv-7rvm-m3vp, inspect your project dependencies for Duplicate Advisory:

inspect dependencies for code.vikunja.io/api

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, where the product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. In Duplicate Advisory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-vfxw-3x8p-2vjr. This link is maintained to preserve external references. ### Original Description Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint.

GHSA-vcgv-7rvm-m3vp Affected Duplicate Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
code.vikunja.io/api
golang/code.vikunja.io/api
Go
≤ 2.5.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vfxw-3x8p-2vjr
NVD — GHSA-vcgv-7rvm-m3vp NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91981
www.vulncheck.com/advisories/vikunja-... WEB
https://www.vulncheck.com/advisories/vikunja-before-2.6.0-user-enumeration-via-v2-api

Frequently Asked Questions

What is GHSA-vcgv-7rvm-m3vp?
GHSA-vcgv-7rvm-m3vp is a security vulnerability in Duplicate Advisory involving Vikunja: Link-share token can enumerate users through the v2 API under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: code.vikunja.io/api.
What version fixes GHSA-vcgv-7rvm-m3vp?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is code.vikunja.io/api affected?
Yes, code.vikunja.io/api is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of GHSA-vcgv-7rvm-m3vp?
GHSA-vcgv-7rvm-m3vp has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with GHSA-vcgv-7rvm-m3vp?
GHSA-vcgv-7rvm-m3vp is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor (The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.).
How can I check Go dependencies for GHSA-vcgv-7rvm-m3vp?
Run the dependency tree command: 'inspect dependencies for code.vikunja.io/api'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vcgv-7rvm-m3vp",
  "modified" : "2026-10-09T20:52:33Z",
  "published" : "2026-09-15T18:32:30Z",
  "withdrawn" : "2026-10-09T20:52:33Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Vikunja: Link-share token can enumerate users through the v2 API",
  "details" : "### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-vfxw-3x8p-2vjr. This link is maintained to preserve external references.\n\n### Original Description\nVikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "code.vikunja.io/api"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.5.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vfxw-3x8p-2vjr"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-91981"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/vikunja-before-2.6.0-user-enumeration-via-v2-api"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-09T20:52:33Z",
    "nvd_published_at" : "2026-09-15T16:17:55Z"
  }
}