/ 
WWW-Mechanize-Cached-1.27_01 UNAUTHORIZED RELEASE
Security Advisories (1)
CVE-2026-8612 (2026-05-15)

WWW::Mechanize::Cached versions before 2.00 for Perl deserialize cached HTTP responses from a world-writable on-disk cache, enabling local response forgery and code execution. With no explicit cache backend, WWW::Mechanize::Cached constructs a default Cache::FileCache under /tmp/FileCache without overriding the backend's documented directory_umask of 000, so the cache root and its subdirectories are created mode 0777 with no sticky bit. Cache entries are named by sha1_hex of the request and read back through Storable::thaw on the next cache hit. A local attacker with write access to the cache tree can replace a victim's cache entry for a known URL with an arbitrary frozen HTTP::Response blob, causing the victim's next get() of that URL to return attacker controlled response bytes. Because the bytes are passed to Storable::thaw, a victim process that has loaded any class with a side-effectful STORABLE_thaw, DESTROY, or overload hook can be escalated to arbitrary code execution.

Changes for version 1.27_01

  • THINGS THAT WILL BREAK YOUR CODE
    • The constructor can no longer take a C<cache> argument to specify the parms for the cache. I'm betting that the functionality where W::M::C instantiates the cache for you isn't actually used. If I break your code, please let me know.
    • Existing caches will not work, because I changed the directory that they get written to. It used to go into /tmp/FileCache/WWW::Mechanize::Cached, but now will go into /tmp/FileCache/www-mechanize-cached. This is so the Windows folks can use the module, too.

Modules

WWW::Mechanize::Cached
Cache response to be polite UNAUTHORIZED

Other files