Read the docs
TI-2026-62108 Aliases CVE-2026-91973GHSA-m469-88xx-8rx2GHSA-p2vv-wrh8-x466

Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuth

Priority HIGH 77CWE-307Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-307.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00672 52nd percentileScored 2026-11-07
Fix Fixed vikunja (go-vikunja): 2.6.0code.vikunja.io/api (Go): 2.6.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
go-vikunjavikunjabefore 2.6.02.6.0Patch availableCNA
—code.vikunja.io/api (Go)before 2.6.02.6.0Patch availableGHSA-m469-88xx-8rx2
  • vikunja Vendorgo-vikunja Affected before 2.6.0 Fixed in 2.6.0 Patch available CNA
  • code.vikunja.io/api (Go) Vendor— Affected before 2.6.0 Fixed in 2.6.0 Patch available GHSA-m469-88xx-8rx2

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:*——go-vikunja
  • cpe:2.3:a:vikunja:vikunja:*:*:*:*:*:*:*:* Versions — — ·go-vikunja

Remediation

  • Fix · CNA vikunja (go-vikunja) Fixed in 2.6.0
  • Fix · GHSA-m469-88xx-8rx2 code.vikunja.io/api (Go) Fixed in 2.6.0 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    go-vikunja vikunja 2.6.0

    13 records Highest priority Priority HIGH 3 HIGH, 7 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-62115 Vikunja before 2.6.0 Privilege Escalation via Link Share HashPriority HIGH 77
    • TI-2026-62107 Vikunja before 2.6.0 Authentication Bypass via Unthrottled APIPriority HIGH 77
    • TI-2026-62106 Vikunja before 2.6.0 Denial of Service via Avatar UploadPriority MEDIUM 64
    Show all 13 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-91973
  2. 2026-10-03 Alias added: GHSA-p2vv-wrh8-x466
  3. 2026-10-10 Alias added: GHSA-m469-88xx-8rx2
  4. 2026-10-10 Fix available: Go/code.vikunja.io/[email protected] · GHSA-m469-88xx-8rx2
  5. 2026-10-10 Weakness changed · GHSA-m469-88xx-8rx2
  6. 2026-10-10 5 new references · GHSA-m469-88xx-8rx2

References

Advisory 2

Other 3

  • TI-2026-40929 Authorization bypass in go-vikunja Vikunja CVSS 4.0CRITICAL 9.3
  • TI-2026-21967 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change CVSS 3.1CRITICAL 9.1
  • TI-2026-62115 Vikunja before 2.6.0 Privilege Escalation via Link Share Hash CVSS 4.0HIGH 8.7
  • TI-2026-62107 Vikunja before 2.6.0 Authentication Bypass via Unthrottled API CVSS 4.0HIGH 8.7
  • TI-2026-26971 Vikunja ahs a TOTP Two-Factor Authentication Bypass via OIDC Login Path CVSS 3.1CRITICAL 9.1
  • TI-2026-48322 Vikunja 0.24.0 Broken Object Level Authorization via Link-Share Token CVSS 4.0CRITICAL 9.3
See all 105 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences