GHSA-m4vj-wr5q-cmvr: Duplicate Advisory Vikunja: Every /api/v2 Pre-auth Endpoint Vulnerability

HIGH
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CVSS 7.5
CWE-307
Published
Advisory Summary

GHSA-m4vj-wr5q-cmvr is a HIGH (CVSS 7.5) vikunja: every /api/v2 pre-auth endpoint vulnerability (CWE-307: Improper Restriction of Excessive Authentication Attempts) affecting Duplicate Advisory libraries in the Go ecosystem. The issue involves vikunja: every /api/v2 pre-auth endpoint is unthrottled on a stock install while its /api/v1 twin is rate limited. Remediation is available in the latest vendor maintenance releases.

GHSA-m4vj-wr5q-cmvr at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-m4vj-wr5q-cmvr
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-307: Improper Restriction of Excessive Authentication Attempts
Affected Product Duplicate Advisory
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

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

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

How to Fix GHSA-m4vj-wr5q-cmvr

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.

github.com/go-vikunja/vikunja fixed: Latest secure release 
Upgrade github.com/go-vikunja/vikunja 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 github.com/go-vikunja/vikunja

How to Check if You Are Affected

To determine whether your application is affected by GHSA-m4vj-wr5q-cmvr, inspect your project dependencies for Duplicate Advisory:

inspect dependencies for github.com/go-vikunja/vikunja

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-307: Improper Restriction of Excessive Authentication Attempts, where the product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame. 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-6rvj-qwjf-3m4q. This link is maintained to preserve external references. ### Original Description Vikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public authentication endpoints including login, register, password-reset, and OAuth token routes. Remote unauthenticated attackers can perform unbounded credential guessing, account enumeration, and password-reset flooding attacks without throttling restrictions.

GHSA-m4vj-wr5q-cmvr Affected Duplicate Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/go-vikunja/vikunja
golang/github.com/go-vikunja/vikunja
Go
≤ 2.5.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6rvj-qwjf-3m4q
NVD — GHSA-m4vj-wr5q-cmvr NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91972
www.vulncheck.com/advisories/vikunja-... WEB
https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-unthrottled-api

Frequently Asked Questions

What is GHSA-m4vj-wr5q-cmvr?
GHSA-m4vj-wr5q-cmvr is a security vulnerability in Duplicate Advisory involving Vikunja: Every /api/v2 pre-auth endpoint is unthrottled on a stock install while its /api/v1 twin is rate limited under CWE-307: Improper Restriction of Excessive Authentication Attempts.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/go-vikunja/vikunja.
What version fixes GHSA-m4vj-wr5q-cmvr?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/go-vikunja/vikunja affected?
Yes, github.com/go-vikunja/vikunja 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-m4vj-wr5q-cmvr?
GHSA-m4vj-wr5q-cmvr has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with GHSA-m4vj-wr5q-cmvr?
GHSA-m4vj-wr5q-cmvr is classified under CWE-307: Improper Restriction of Excessive Authentication Attempts (The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.).
How can I check Go dependencies for GHSA-m4vj-wr5q-cmvr?
Run the dependency tree command: 'inspect dependencies for github.com/go-vikunja/vikunja'. 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-m4vj-wr5q-cmvr",
  "modified" : "2026-10-09T20:50:59Z",
  "published" : "2026-09-15T18:32:30Z",
  "withdrawn" : "2026-10-09T20:50:59Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Vikunja: Every /api/v2 pre-auth endpoint is unthrottled on a stock install while its /api/v1 twin is rate limited",
  "details" : "### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-6rvj-qwjf-3m4q. This link is maintained to preserve external references.\n\n### Original Description\nVikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public authentication endpoints including login, register, password-reset, and OAuth token routes. Remote unauthenticated attackers can perform unbounded credential guessing, account enumeration, and password-reset flooding attacks without throttling restrictions.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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" : "github.com/go-vikunja/vikunja"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.5.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6rvj-qwjf-3m4q"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-91972"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-unthrottled-api"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-307" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-09T20:50:59Z",
    "nvd_published_at" : "2026-09-15T16:17:54Z"
  }
}