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

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.

Published: 2025-09-03 Last update: 2025-10-20 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-58351 is rated Low Risk (34.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.07%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-58351

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-20 0.02% 0.07% +0.04%
2 2026-01-30 0.06% 0.02% -0.04%
3 2026-01-03 0.06%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-58351

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.3 4.0 [email protected]

Weakness enumeration for CVE-2025-58351

Affected software / configurations for CVE-2025-58351

Vendor Product Version Raw CPE
getoutline outline >= 0.72.0, < 0.84.0 cpe:2.3:a:getoutline:outline:*:*:*:*:*:*:*:*

References for CVE-2025-58351

cvelogic Threat Intelligence