# CVE-2020-8927: Buffer overflow in Brotli library

> An attacker can cause a denial of service by triggering a buffer overflow in the Brotli library during one-shot decompression of large data chunks.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Sep 2020
- **Updated:** 29 May 2026
- **Also known as:** ALPINE-CVE-2020-8927, ALSA-2021:1702, AZL-6341, CLEANSTART-2024-XN11840, DEBIAN-CVE-2020-8927, DLA-2476-1, DSA-4801-1, MGASA-2020-0385, RHSA-2021:1702, RLSA-2021:1702, SUSE-SU-2021:3942-1, SUSE-SU-2023:3669-1, SUSE-SU-2023:3670-1, SUSE-SU-2023:3827-1, SUSE-SU-2024:1968-1, SUSE-SU-2025:01762-1, UBUNTU-CVE-2020-8927, USN-4568-1, openSUSE-SU-2020:1578-1, openSUSE-SU-2021:3942-1, openSUSE-SU-2024:11708-1, openSUSE-SU-2024:13224-1, openSUSE-SU-2026:11988-1

## What is CVE-2020-8927?

CVE-2020-8927 is a medium-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 15 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A buffer overflow exists in the Brotli library versions prior to 1.0.8 where an attacker controlling the input length of a "one-shot" decompression request to a script can trigger a crash, which happens when copying over chunks of data larger than 2 GiB. It is recommended to update your Brotli library to 1.0.8 or later. If one cannot update, we recommend to use the "streaming" API as opposed to the "one-shot" API, and impose chunk size limits.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-130 (Improper Handling of Length Parameter Inconsistency)

## Which versions are affected by CVE-2020-8927?

It affects 10 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `brotli` | AlmaLinux:8 | All versions | 1.0.6-3.el8 |
| `brotli-devel` | AlmaLinux:8 | All versions | 1.0.6-3.el8 |
| `python3-brotli` | AlmaLinux:8 | All versions | 1.0.6-3.el8 |
| `brotli-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.6-3.el8 |
| `brotli-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.6-3.el8 |
| `brotli-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.6-3.el8 |
| `python3-brotli` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.6-3.el8 |
| `python3-brotli-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.0.6-3.el8 |
| `brotli` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.0.6-3.el8 |
| `brotli-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.0.6-3.el8 |
| `brotli-debugsource` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.0.6-3.el8 |
| `python3-brotli-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:1.0.6-3.el8 |
| `brotli` | Rocky Linux:8 | All versions | 0:1.0.6-3.el8 |
| `brotli` | SUSE:Linux Enterprise Micro 5.1 | All versions | 1.0.7-3.3.1 |
| `brotli` | SUSE:Linux Enterprise Module for Basesystem 15 SP2 | All versions | 1.0.7-3.3.1 |
| `brotli` | SUSE:Linux Enterprise Module for Basesystem 15 SP3 | All versions | 1.0.7-3.3.1 |
| `python-brotlipy` | SUSE:Linux Enterprise Module for Public Cloud 12 | All versions | 0.6.0-2.6.1 |
| `python-brotlipy` | SUSE:Linux Enterprise Module for Public Cloud 15 SP1 | All versions | 0.7.0-150100.3.6.1 |
| `python-brotlipy` | SUSE:Linux Enterprise Module for Public Cloud 15 SP2 | All versions | 0.7.0-150100.3.6.1 |
| `python-brotlipy` | SUSE:Linux Enterprise Module for Public Cloud 15 SP3 | All versions | 0.7.0-150300.3.3.1 |
| `python-brotlipy` | SUSE:Linux Enterprise Module for Public Cloud 15 SP4 | All versions | 0.7.0-150300.3.3.1 |
| `python-brotlipy` | SUSE:Linux Enterprise Module for Public Cloud 15 SP5 | All versions | 0.7.0-150300.3.3.1 |
| `python-Brotli` | SUSE:Linux Enterprise Module for Python 3 15 SP6 | All versions | 1.0.7-150200.3.3.1 |
| `python-Brotli` | SUSE:Linux Enterprise Module for Server Applications 15 SP5 | All versions | 1.0.7-150200.3.3.1 |
| `brotli` | openSUSE:Leap 15.2 | All versions | 1.0.9-lp152.2.3.1 |
| `brotli` | openSUSE:Leap 15.3 | All versions | 1.0.7-3.3.1 |
| `python-brotlipy` | openSUSE:Leap 15.4 | All versions | 0.7.0-150300.3.3.1 |
| `python-Brotli` | openSUSE:Leap 15.5 | All versions | 1.0.7-150200.3.3.1 |
| `python-brotlipy` | openSUSE:Leap 15.5 | All versions | 0.7.0-150300.3.3.1 |
| `cargo-audit-advisory-db` | openSUSE:Tumbleweed | All versions | 20220105-1.1 |
| `python-Brotli` | openSUSE:Tumbleweed | All versions | 1.2.0-1.6 |

Products: Canonical Ubuntu Linux, Debian Debian Linux, Fedoraproject Fedora, Google Brotli, Microsoft .Net, Microsoft .Net Core, Microsoft Powershell, Microsoft Visual Studio 2019, Microsoft Visual Studio 2022, Opensuse Leap.

## How do I fix CVE-2020-8927?

Upgrade to a fixed version.

## Is CVE-2020-8927 being exploited?

There is no known exploitation of CVE-2020-8927 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-11651](https://insights.sbomify.com/CVE-2020-11651/): SaltStack Salt Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2020-7247](https://insights.sbomify.com/CVE-2020-7247/): OpenSMTPD Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16928](https://insights.sbomify.com/CVE-2019-16928/): Exim Out-of-bounds Write (critical 9.8, exploited in the wild)
- [CVE-2018-6789](https://insights.sbomify.com/CVE-2018-6789/): Exim Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2015-2590](https://insights.sbomify.com/CVE-2015-2590/): Oracle Java SE and Java SE Embedded Remote Code Execution (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8927 and fix it if it is affected.

What it is: CVE-2020-8927 is a medium-severity memory corruption vulnerability in Canonical Ubuntu Linux, published on 15 Sep 2020. 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-2020-8927 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. 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-2020-8927/ (Markdown: https://insights.sbomify.com/CVE-2020-8927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8927
- OSV: https://osv.dev/vulnerability/CVE-2020-8927

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-8927/
Summaries are generated and may contain mistakes; the official description above is the record.