# CVE-2026-109206: LogicalDOC Community Edition through 9.3 Username Enumeration via AvatarServlet

> Unauthenticated attackers can enumerate valid usernames and retrieve profile pictures in LogicalDOC Community Edition via the AvatarServlet.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2026
- **Updated:** 13 Oct 2026
- **Also known as:** GHSA-g7j6-49p3-h792

## What is CVE-2026-109206?

CVE-2026-109206 is a medium-severity vulnerability in LogicalDOC Community Edition, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

LogicalDOC Community Edition through 9.3 contains a username enumeration vulnerability that allows unauthenticated attackers to identify valid accounts because the AvatarServlet (/avatar) performs no session validation. Attackers can supply usernames or numeric IDs in the userId parameter and compare 1x1 transparent images against real avatars to enumerate users and retrieve profile pictures.

Weakness: CWE-204 (Observable Response Discrepancy)

## Which versions are affected by CVE-2026-109206?


## How do I fix CVE-2026-109206?

No fix has been published for CVE-2026-109206 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-109206 being exploited?

There is no known exploitation of CVE-2026-109206 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-109206 and fix it if it is affected.

What it is: CVE-2026-109206 is a medium-severity vulnerability in LogicalDOC Community Edition, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-109206 in the wild and no public exploit code.

Affected product: LogicalDOC Community Edition. 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-2026-109206/ (Markdown: https://insights.sbomify.com/CVE-2026-109206/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-109206
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109206
- OSV: https://osv.dev/vulnerability/CVE-2026-109206

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-109206/
Summaries are generated and may contain mistakes; the official description above is the record.