# CVE-2025-49643: Frontend DoS vulnerability due to asymmetric resource consumption

> An authenticated Zabbix user can cause server CPU exhaustion via crafted requests to imgstore.php, leading to denial of service.

- **Severity:** Medium 6.0 (`CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Dec 2025
- **Updated:** 1 Dec 2025
- **Also known as:** DEBIAN-CVE-2025-49643, GHSA-728r-qj99-48p2, UBUNTU-CVE-2025-49643

## What is CVE-2025-49643?

CVE-2025-49643 is a medium-severity denial of service vulnerability in Zabbix, published on 1 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An authenticated Zabbix user (including Guest) is able to cause disproportionate CPU load on the webserver by sending specially crafted parameters to /imgstore.php, leading to potential denial of service.

Weakness: CWE-405 (Asymmetric Resource Consumption (Amplification))

## Which versions are affected by CVE-2025-49643?

It affects 1 product.


Products: Zabbix Frontend.

## How do I fix CVE-2025-49643?

Apply the vendor's patch.

## Is CVE-2025-49643 being exploited?

There is no known exploitation of CVE-2025-49643 in the wild and no public exploit code.

## Other vulnerabilities in Zabbix

- [CVE-2023-32725](https://insights.sbomify.com/CVE-2023-32725/): Leak of zbx_session cookie when using a scheduled report that includes a dashboard with a URL widget. (critical 9.6)
- [CVE-2025-27232](https://insights.sbomify.com/CVE-2025-27232/): Frontend arbitrary file read in oauth.authorize action (medium 6.8)
- [CVE-2023-29457](https://insights.sbomify.com/CVE-2023-29457/): Insufficient validation of Action form input fields (medium 6.3)
- [CVE-2023-29456](https://insights.sbomify.com/CVE-2023-29456/): Inefficient URL schema validation (medium 5.7)
- [CVE-2023-29454](https://insights.sbomify.com/CVE-2023-29454/): Persistent XSS in the user form (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-49643 and fix it if it is affected.

What it is: CVE-2025-49643 is a medium-severity denial of service vulnerability in Zabbix, published on 1 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-49643 in the wild and no public exploit code.

Affected product: Zabbix. 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-2025-49643/ (Markdown: https://insights.sbomify.com/CVE-2025-49643/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-49643
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-49643
- OSV: https://osv.dev/vulnerability/CVE-2025-49643

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-49643/
Summaries are generated and may contain mistakes; the official description above is the record.