Quick answers
- Is CVE-2026-8612 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-8612 being exploited in the wild.
- How severe is CVE-2026-8612?
- Medium severity, with a CVSS score of 5.3, published 15 May 2026.
- Which products and versions are affected?
- Libwww-Perl WWW::Mechanize::Cached < 2.00.
- Is there a fix for CVE-2026-8612?
- A patch was published on 2026-05-14: Version 2.00 released. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-8612 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-8612?
- Check whether you run Libwww-Perl WWW::Mechanize::Cached or Oalders Www\ at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
WWW::Mechanize::Cached (before version 2.00) defaults to using Cache::FileCache in /tmp/FileCache with a directory_umask of 000. This results in world-writable (0777) cache directories without a sticky bit. A local attacker can identify a victim's cache entry (keyed by SHA1 hash of the URL) and replace it with a malicious serialized HTTP::Response object. When the victim retrieves the cached URL, the library uses Storable::thaw to deserialize the attacker-controlled data. If the victim's process has loaded classes with side-effectful methods (such as STORABLE_thaw or DESTROY), this leads to arbitrary code execution. The fix in version 2.00 moves the default cache to the user's XDG cache home and enforces a umask of 077.
Affected products
- libwww-perl WWW::Mechanize::Cached < 2.00
Timeline
- 2026-05-13: disclosed: Issue reported to maintainers.
- 2026-05-14: patched: Version 2.00 released.
- 2026-05-15: advisory: Public disclosure via oss-security and NVD.