Read the docs

Memory exhaustion in Vikunja via unbounded avatar size cache

Priority MEDIUM 46CWE-770Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

Vikunja before 2.7.1 contains an uncontrolled resource consumption flaw in its avatar handling (CWE-770). Authenticated users can exhaust server memory by requesting an avatar at many distinct sizes up to 1024, because each size is cached without eviction. The cache grows by roughly a gigabyte per account and can cause the API process to be OOM-killed.

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

Description from the CNA

Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated users to exhaust server memory by requesting avatars at many distinct sizes. Attackers can upload a noisy avatar and fetch it at each size up to 1024, caching roughly a gigabyte per account without eviction and causing the API process to be OOM-killed.

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

Upgrade Vikunja to 2.7.1, the fixed version for go-vikunja/vikunja.

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

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123523
  2. 2026-11-08 Alias added: GHSA-w5pw-69q7-rf8x

References

  • 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