# CVE-2019-11922: Race condition in Zstandard

> A race condition in Zstandard's one-pass compression allows attackers to write bytes out of bounds if a small output buffer is used, potentially leading to code execution or crashes.

- **Severity:** High 8.1 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jul 2019
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2019-11922, CLEANSTART-2025-JH01650, DEBIAN-CVE-2019-11922, MGASA-2019-0257, UBUNTU-CVE-2019-11922, USN-4108-1, USN-5593-1, openSUSE-SU-2019:1845-1, openSUSE-SU-2019:1952-1, openSUSE-SU-2019:2008-1, openSUSE-SU-2024:11544-1

## What is CVE-2019-11922?

CVE-2019-11922 is a high-severity vulnerability in Facebook Zstandard, published on 25 Jul 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A race condition in the one-pass compression functions of Zstandard prior to version 1.3.8 could allow an attacker to write bytes out of bounds if an output buffer smaller than the recommended size was used.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2019-11922?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `zstd` | SUSE:Package Hub 15 | All versions | 1.4.2-bp151.4.3.1 |
| `zstd` | SUSE:Package Hub 15 SP1 | All versions | 1.4.2-bp151.4.3.1 |
| `zstd` | openSUSE:Leap 15.0 | All versions | 1.4.2-lp150.2.3.1 |
| `zstd` | openSUSE:Leap 15.1 | All versions | 1.4.2-lp151.3.3.1 |
| `zstd` | openSUSE:Tumbleweed | All versions | 1.5.0-1.13 |

Products: Facebook Zstandard.

## How do I fix CVE-2019-11922?

Upgrade to a fixed version.

## Is CVE-2019-11922 being exploited?

There is no known exploitation of CVE-2019-11922 in the wild and no public exploit code.

## Other vulnerabilities in Facebook Zstandard

- [CVE-2022-4899](https://insights.sbomify.com/CVE-2022-4899/): zstd vulnerable to buffer overrun (high 7.5)
- [CVE-2021-24031](https://insights.sbomify.com/CVE-2021-24031/): Information disclosure in Zstandard (medium 5.5)
- [CVE-2021-24032](https://insights.sbomify.com/CVE-2021-24032/): Information disclosure in Zstandard (medium 4.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-11922 and fix it if it is affected.

What it is: CVE-2019-11922 is a high-severity vulnerability in Facebook Zstandard, published on 25 Jul 2019. 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-2019-11922 in the wild and no public exploit code.

Affected product: Facebook Zstandard. 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-2019-11922/ (Markdown: https://insights.sbomify.com/CVE-2019-11922/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-11922
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-11922
- OSV: https://osv.dev/vulnerability/CVE-2019-11922

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-11922/
Summaries are generated and may contain mistakes; the official description above is the record.