CVE-2026-8612
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.
- Score
- CVSS 3.1 5.3 Medium
- Status
- Analyzed - 9b29abf9-4ab0-4765-b253-1875cd9b441e
- Published
- 2026-05-15
- Last modified
- 2026-10-26
- Weaknesses
- CWE-502, CWE-732
Affected products
References
- https://github.com/libwww-perl/WWW-Mechanize-Cached/pull/36
- https://github.com/libwww-perl/WWW-Mechanize-Cached/commit/b821647deeedf83490ebc1db91d959d942300ce0.patch
- https://metacpan.org/release/OALDERS/WWW-Mechanize-Cached-2.00/changes
- http://www.openwall.com/lists/oss-security/2026/05/15/1
