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.
Problem types
Product status
Any version
Credits
Ron Edgerson
References
github.com/madler/zlib/issues/1142
seclists.org/fulldisclosure/2026/Jan/3
zlib.net/
github.com/madler/zlib
www.vulncheck.com/...ntgz-global-buffer-overflow-in-tgzfname