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TI-2026-62111 Aliases CVE-2026-91981GHSA-vcgv-7rvm-m3vpGHSA-vfxw-3x8p-2vjr

Vikunja before 2.6.0 User Enumeration via v2 API

Priority MEDIUM 57CWE-200Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-200 and CWE-863.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00306 23rd 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
No
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-vfxw-3x8p-2vjr
  • 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-vfxw-3x8p-2vjr

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-vfxw-3x8p-2vjr 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-2026-62108 Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuthPriority HIGH 77
    • TI-2026-62107 Vikunja before 2.6.0 Authentication Bypass via Unthrottled APIPriority HIGH 77
    Show all 13 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-91981
  2. 2026-10-03 Alias added: GHSA-vcgv-7rvm-m3vp
  3. 2026-10-10 Alias added: GHSA-vfxw-3x8p-2vjr
  4. 2026-10-10 Fix available: Go/code.vikunja.io/[email protected] · GHSA-vfxw-3x8p-2vjr
  5. 2026-10-10 CVSS score added · GHSA-vfxw-3x8p-2vjr
  6. 2026-10-10 Weakness changed · GHSA-vfxw-3x8p-2vjr
  7. 2026-10-10 5 new references · GHSA-vfxw-3x8p-2vjr

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-2026-62108 Vikunja before 2.6.0 Authentication Bypass via CalDAV BasicAuth 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
See all 105 →

Sources

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