# CVE-2026-123523: Vikunja uncontrolled resource consumption in avatar cache

Source: https://junglewise.ai/threats/cve-2026-123523-vikunja-before-2-7-1-contains-an-uncontrolled-resource  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-08. Updated: 2026-11-08  
License: CC BY 4.0 with a link back

CVE-2026-123523 · Severity: medium · CVSS 6.5 · Published 2026-11-08

Vikunja is a task and project management application used to organize work and collaborate on tasks. An authenticated user can exhaust the server's memory by uploading an avatar and repeatedly requesting it at different sizes, causing the API process to crash and making the service unavailable.

Technologies: [Vikunja](https://junglewise.ai/threats/technologies/vikunja). Vendors: [Vikunja](https://junglewise.ai/threats/vendors/vikunja).

## Quick answers

**Is CVE-2026-123523 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123523 being exploited in the wild.

**How severe is CVE-2026-123523?** Medium severity, with a CVSS score of 6.5, published 8 November 2026.

**Which products and versions are affected?** Vikunja before 2.7.1.

**Is there a fix for CVE-2026-123523?** Yes: fixed in 2.7.1. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-123523 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-123523?** Check whether you run Vikunja at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 2.7.1

## Technical details

The avatar endpoint caches resized copies of avatars for each requested size (1–1024) with no TTL or eviction policy, storing them in an unbounded in-memory map. An authenticated attacker uploads a noisy avatar and requests it at many distinct sizes, accumulating roughly 1 GB of memory per account that persists until restart or avatar change. The vulnerability requires authentication but no user interaction from victims, and rate limiting is disabled by default.

## Affected products

- Vikunja Vikunja before 2.7.1

## Timeline

- 2026-10-22: disclosed
- 2026-11-08: advisory

## References

- [https://github.com/go-vikunja/vikunja/security/advisories/GHSA-3x3m-2j93-w46j](https://github.com/go-vikunja/vikunja/security/advisories/GHSA-3x3m-2j93-w46j)
- [https://www.vulncheck.com/advisories/vikunja-before-2.7.1-memory-exhaustion-via-unbounded-avatar-size-cache](https://www.vulncheck.com/advisories/vikunja-before-2.7.1-memory-exhaustion-via-unbounded-avatar-size-cache)

## Related threats

- [Vikunja denial of service via pagination bypass in API v1](https://junglewise.ai/threats/cve-2026-123531-vikunja-from-1-0-0-before-2-7-1-contains-an-uncontrolled)
- [Vikunja missing authentication in TOTP enrollment](https://junglewise.ai/threats/cve-2026-123530-vikunja-before-2-7-1-contains-a-missing-authentication)
- [Vikunja stored CSS injection in rich-text table cells](https://junglewise.ai/threats/cve-2026-123529-vikunja-before-2-7-1-contains-a-stored-css-injection)
- [Vikunja insufficient session expiration in HTTP token middleware](https://junglewise.ai/threats/cve-2026-123528-vikunja-before-2-7-1-contains-an-insufficient-session-expiration)
- [Vikunja API token authorization bypass in v1/v2 collision](https://junglewise.ai/threats/cve-2026-123527-vikunja-from-2-4-0-before-2-7-1-contains-an-authorization-bypass)