# CVE-2026-22184: zlib <= 1.3.1.2 untgz Global Buffer Overflow in TGZfname()

> A buffer overflow in the untgz utility allows attackers to execute arbitrary code or cause denial of service via a long archive name.

- **Severity:** Medium 4.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 7 Jan 2026
- **Updated:** 1 Sep 2026
- **Also known as:** ALPINE-CVE-2026-22184, AZL-73964, AZL-73967, AZL-73991, AZL-73994, AZL-74003, CLEANSTART-2026-GM38314, DEBIAN-CVE-2026-22184, ECHO-0c2a-94bf-ba6a, GHSA-7687-3v4j-49fr, MGASA-2026-0006, MINI-w4p6-33x2-v3jq, UBUNTU-CVE-2026-22184

## What is CVE-2026-22184?

CVE-2026-22184 is a medium-severity memory corruption vulnerability in zlib, published on 7 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

zlib versions up to and including 1.3.1.2 include a global buffer overflow in the untgz utility located under contrib/untgz. The vulnerability is limited to the standalone demonstration utility and does not affect the core zlib compression library. The flaw occurs when a user executes the untgz command with an excessively long archive name supplied via the command line, leading to an out-of-bounds write in a fixed-size global buffer.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input), CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-22184?

It affects 1 product.


Products: Zlib Zlib.

## How do I fix CVE-2026-22184?

Upgrade to a fixed version.

## Is CVE-2026-22184 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22184 exists.

## Other vulnerabilities in zlib

- [CVE-2002-0059](https://insights.sbomify.com/CVE-2002-0059/): Use after free in n/a (critical 9.8)
- [CVE-2005-2096](https://insights.sbomify.com/CVE-2005-2096/): Memory corruption in n/a (high 7.5)
- [CVE-2003-0107](https://insights.sbomify.com/CVE-2003-0107/): Memory corruption in n/a (high 7.5)
- [CVE-2005-1849](https://insights.sbomify.com/CVE-2005-1849/): Denial of service in n/a (medium 5.0)
- [CVE-2026-27171](https://insights.sbomify.com/CVE-2026-27171/): Denial of service in zlib (low 2.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-22184 and fix it if it is affected.

What it is: CVE-2026-22184 is a medium-severity memory corruption vulnerability in zlib, published on 7 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22184 exists.

Affected product: zlib. 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-2026-22184/ (Markdown: https://insights.sbomify.com/CVE-2026-22184/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-22184
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-22184
- OSV: https://osv.dev/vulnerability/CVE-2026-22184

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-22184/
Summaries are generated and may contain mistakes; the official description above is the record.