# CVE-2019-25337: OwnCloud 8.1.8 - Username Disclosure

> Remote attackers can enumerate user accounts and retrieve user information via the share.php endpoint in OwnCloud.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Feb 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-v5m9-phxh-m6wj

## What is CVE-2019-25337?

CVE-2019-25337 is a medium-severity vulnerability in OwnCloud, published on 12 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2019-25337?


## How do I fix CVE-2019-25337?

No fix has been published for CVE-2019-25337 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-25337 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25337 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-25337 and fix it if it is affected.

What it is: CVE-2019-25337 is a medium-severity vulnerability in OwnCloud, published on 12 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25337 exists.

Affected product: OwnCloud. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2019-25337/ (Markdown: https://insights.sbomify.com/CVE-2019-25337/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-25337
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-25337
- OSV: https://osv.dev/vulnerability/CVE-2019-25337

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-25337/
Summaries are generated and may contain mistakes; the official description above is the record.