zlib up to 1.3.1.2 untgz TGZfname argv[] buffer overflow

Summaryinfo

A vulnerability, which was classified as critical, was found in zlib up to 1.3.1.2. Affected by this vulnerability is the function TGZfname of the component untgz. Executing a manipulation of the argument argv[] can lead to buffer overflow. This vulnerability is tracked as CVE-2026-22184. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability classified as critical was found in zlib up to 1.3.1.2. This vulnerability affects the function TGZfname of the component untgz. The manipulation of the argument argv[] with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was disclosed by Ron Edgerson. The advisory is available at seclists.org. This vulnerability was named CVE-2026-22184 since 01/06/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 03/18/2026).

The vulnerability scanner Nessus provides a plugin with the ID 282443 (Linux Distros Unpatched Vulnerability : CVE-2026-22184), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (282443), EUVD (EUVD-2026-1173) and CERT Bund (WID-SEC-2026-0045). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Open Source zlib

Productinfo

Name

• zlib

Version

• 1.3.1.0
• 1.3.1.1
• 1.3.1.2

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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