GHSA-p2vv-wrh8-x466: Duplicate Advisory Remote Code Execution Vulnerability

HIGH
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CVSS 7.5
CWE-307
Published
Advisory Summary

GHSA-p2vv-wrh8-x466 is a HIGH (CVSS 7.5) remote code execution vulnerability (CWE-307: Improper Restriction of Excessive Authentication Attempts) affecting Duplicate Advisory libraries in the Go ecosystem. The issue involves vikunja: caldav and feeds basicauth endpoints have no rate limit, bypassing the anti-brute-force floor on account passwords. Remediation is available in the latest vendor maintenance releases.

GHSA-p2vv-wrh8-x466 at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-p2vv-wrh8-x466
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-p2vv-wrh8-x466

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-p2vv-wrh8-x466, 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-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-m469-88xx-8rx2. This link is maintained to preserve external references. ### Original Description Vikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth endpoints that lack rate limiting protection. Remote unauthenticated attackers can issue unbounded credential-guessing requests against /dav, /.well-known, and /feeds routes to bypass the instance's anti-brute-force controls and compromise password-only accounts.

GHSA-p2vv-wrh8-x466 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-m469-88xx-8rx2
NVD — GHSA-p2vv-wrh8-x466 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91973
www.vulncheck.com/advisories/vikunja-... WEB
https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-caldav-basicauth

Frequently Asked Questions

What is GHSA-p2vv-wrh8-x466?
GHSA-p2vv-wrh8-x466 is a security vulnerability in Duplicate Advisory involving Vikunja: CalDAV and feeds BasicAuth endpoints have no rate limit, bypassing the anti-brute-force floor on account passwords 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: code.vikunja.io/api.
What version fixes GHSA-p2vv-wrh8-x466?
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-p2vv-wrh8-x466?
GHSA-p2vv-wrh8-x466 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-p2vv-wrh8-x466?
GHSA-p2vv-wrh8-x466 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-p2vv-wrh8-x466?
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-p2vv-wrh8-x466",
  "modified" : "2026-10-09T20:51:57Z",
  "published" : "2026-09-15T18:32:30Z",
  "withdrawn" : "2026-10-09T20:51:57Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Vikunja: CalDAV and feeds BasicAuth endpoints have no rate limit, bypassing the anti-brute-force floor on account passwords",
  "details" : "### Duplicate Advisory\nThis advisory has been withdrawn because it is a duplicate of GHSA-m469-88xx-8rx2. This link is maintained to preserve external references.\n\n### Original Description\nVikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth endpoints that lack rate limiting protection. Remote unauthenticated attackers can issue unbounded credential-guessing requests against /dav, /.well-known, and /feeds routes to bypass the instance's anti-brute-force controls and compromise password-only accounts.",
  "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" : "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-m469-88xx-8rx2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-91973"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-caldav-basicauth"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-307" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-09T20:51:57Z",
    "nvd_published_at" : "2026-09-15T16:17:54Z"
  }
}