What is the CVSS score of CVE-2019-25337?

CVE-2019-25337 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of PHP are affected by CVE-2019-25337?

OwnCloud 8.1.8 instances are vulnerable to username enumeration attacks that allow unauthenticated attackers to systematically discover valid user accounts through the share.php endpoint.

Is there a public PoC exploit available for CVE-2019-25337?

Yes, a public proof-of-concept exploit is available for CVE-2019-25337. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2019-25337?

Within 24 hours: Inventory all OwnCloud 8.1.8 deployments and disable or restrict public access to share.php endpoint via WAF or network controls. Within 7 days: Implement rate limiting and access logging on share.php to detect exploitation attempts; notify users of potential account enumeration. Within 30 days: Migrate to a supported OwnCloud version or evaluate alternative file-sharing solutions with active security support.

PHP CVE-2019-25337

CRITICAL

Observable Discrepancy (CWE-203)

2026-02-12 disclosure@vulncheck.com

PHP

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:02 vuln.today

PoC Detected

Feb 13, 2026 - 14:23 vuln.today

Public exploit code

CVE Published

Feb 12, 2026 - 23:16 nvd

CRITICAL 9.8

DescriptionCVE.org

OwnCloud 8.1.8 contains a username enumeration vulnerability that allows remote attackers to discover user accounts by manipulating the share.php endpoint. Attackers can send crafted GET requests to /index.php/core/ajax/share.php with a wildcard search parameter to retrieve comprehensive user information.