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TI-2026-86663 Aliases CVE-2026-123521GHSA-8h95-jvr5-q5cg

Unthrottled password guessing in Vikunja lets attackers disable TOTP

Priority MEDIUM 42CWE-307Published · Updated

Key facts

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

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

Summary

Vikunja before 2.7.1 does not restrict excessive authentication attempts (CWE-307). An attacker holding a stolen session can guess the account password through the TOTP disable endpoint without any lockout. A correct guess lets the attacker disable TOTP without a code, which gives persistent takeover of the account.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

Description from the CNA

Vikunja before 2.7.1 contains an improper restriction of excessive authentication attempts vulnerability that allows session holders to brute-force account passwords via unthrottled re-authentication endpoints. Attackers with a stolen session can guess the password via /user/settings/totp/disable without lockout, then disable TOTP without a code for persistent account takeover.

Why it matters now

Fix Fixed vikunja (go-vikunja): 2.7.1

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
go-vikunjavikunjabefore 2.7.12.7.1Patch availableCNA
  • vikunja Vendorgo-vikunja Affected before 2.7.1 Fixed in 2.7.1 Patch available CNA

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

The fix is in Vikunja 2.7.1, so upgrade the vikunja package to 2.7.1.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

  • Fix · CNA vikunja (go-vikunja) Fixed in 2.7.1

Fixed in the same release

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

  • Release ·

    go-vikunja vikunja 2.7.1

    39 records Highest priority Priority MEDIUM 20 MEDIUM, 19 LOW

    Other records, highest priority first

    • TI-2026-86673 Pagination limit bypass in Vikunja lets users exhaust resourcesPriority MEDIUM 53
    • TI-2026-86654 Vikunja exposes password-reset tokens in access logsPriority MEDIUM 52
    • TI-2026-86670 Insufficient session expiration in Vikunja token middlewarePriority MEDIUM 48
    Show all 39 records →

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123521
  2. 2026-11-08 Alias added: GHSA-8h95-jvr5-q5cg

References

Advisory 1

  • 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