# CVE-2020-36846: IO::Compress::Brotli versions prior to 0.007 for Perl have an integer overflow in the bundled Brotli C library

> An integer overflow in the bundled Brotli library allows attackers to cause a denial of service via large decompression inputs.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/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:** 30 May 2025
- **Updated:** 30 May 2025
- **Also known as:** GHSA-44qx-v2f9-7rq9, UBUNTU-CVE-2020-36846

## What is CVE-2020-36846?

CVE-2020-36846 is a critical vulnerability in TIMLEGGE IO::Compress::Brotli, published on 30 May 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A buffer overflow, as described in CVE-2020-8927, exists in the embedded Brotli library.  Versions of IO::Compress::Brotli prior to 0.007 included a version of the brotli library prior to version 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 IO::Compress::Brotli module to 0.007 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-1395 (Dependency on Vulnerable Third-Party Component)

## Which versions are affected by CVE-2020-36846?


## How do I fix CVE-2020-36846?

Upgrade to a fixed version.

## Is CVE-2020-36846 being exploited?

There is no known exploitation of CVE-2020-36846 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36846 and fix it if it is affected.

What it is: CVE-2020-36846 is a critical vulnerability in TIMLEGGE IO::Compress::Brotli, published on 30 May 2025. 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-2020-36846 in the wild and no public exploit code.

Affected product: TIMLEGGE IO::Compress::Brotli. 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-2020-36846/ (Markdown: https://insights.sbomify.com/CVE-2020-36846/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36846
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36846
- OSV: https://osv.dev/vulnerability/CVE-2020-36846

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-36846/
Summaries are generated and may contain mistakes; the official description above is the record.