# CVE-2019-16536: Stack overflow leading to DoS can be triggered by a malicious authenticated client.

> A malicious authenticated client can trigger a stack overflow leading to denial of service in ClickHouse.

- **Severity:** High 8.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 May 2025
- **Updated:** 21 May 2025
- **Also known as:** DEBIAN-CVE-2019-16536, ECHO-b165-83cf-9a1b, GHSA-5xwv-wjhm-pv8f, UBUNTU-CVE-2019-16536

## What is CVE-2019-16536?

CVE-2019-16536 is a high-severity denial of service vulnerability in Clickhouse DB, published on 21 May 2025. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Stack overflow leading to DoS can be triggered by a malicious authenticated client in Clickhouse before 19.14.3.3.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2019-16536?

It affects 1 product.


Products: Clickhouse Clickhouse.

## How do I fix CVE-2019-16536?

No fix has been published for CVE-2019-16536 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-16536 being exploited?

There is no known exploitation of CVE-2019-16536 in the wild and no public exploit code.

## Other vulnerabilities in Clickhouse DB

- [CVE-2019-16535](https://insights.sbomify.com/CVE-2019-16535/): Memory corruption in ClickHouse (critical 9.8)
- [CVE-2018-14670](https://insights.sbomify.com/CVE-2018-14670/): Missing authorization in ClickHouse (critical 9.8)
- [CVE-2018-14671](https://insights.sbomify.com/CVE-2018-14671/): Code injection in ClickHouse (critical 9.8)
- [CVE-2021-43304](https://insights.sbomify.com/CVE-2021-43304/): Memory corruption in clickhouse (high 8.8)
- [CVE-2021-43305](https://insights.sbomify.com/CVE-2021-43305/): Memory corruption in clickhouse (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-16536 and fix it if it is affected.

What it is: CVE-2019-16536 is a high-severity denial of service vulnerability in Clickhouse DB, published on 21 May 2025. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-16536 in the wild and no public exploit code.

Affected product: Clickhouse DB. 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-2019-16536/ (Markdown: https://insights.sbomify.com/CVE-2019-16536/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-16536
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-16536
- OSV: https://osv.dev/vulnerability/CVE-2019-16536

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-16536/
Summaries are generated and may contain mistakes; the official description above is the record.