What happened
Critical zlib untgz buffer overflow vulnerability was disclosed in the widely used zlib compression library’s untgz utility (versions up to 1.3.1.2), where improper handling of command-line input in the TGZfname() function leads to an unbounded strcpy() into a fixed-size global buffer, causing a global buffer overflow. This flaw, tracked as CVE-2026-22184, occurs before any archive parsing or validation, allowing an attacker to trigger memory corruption, denial of service, or potential code execution by supplying an overly long archive name. The vulnerability affects systems and applications that invoke the untgz utility as part of file extraction processes and is considered severe due to its trivial exploitability via command-line arguments without authentication.
Who is affected
Developers and systems that incorporate zlib’s untgz utility in build pipelines, Linux distributions, embedded environments, or other automated workflows face direct exposure to memory corruption risks due to this vulnerability.
Why CISOs should care
This buffer overflow highlights how foundational third-party libraries can introduce critical risks across enterprise environments, especially where automation tools or extraction utilities are used without adequate input validation controls.
3 practical actions
- Update zlib components: Replace affected zlib versions with patched releases that mitigate CVE-2026-22184.
- Validate input lengths: Implement checks on archive name lengths in scripts that invoke untgz.
- Audit build pipelines: Review automated processes that rely on untgz to prevent exploitation in CI/CD environments.