CVE-2026-74883

openssl_encrypt versions before 1.4.0 contain a sandbox bypass (CWE-693, protection mechanism failure) in which the plugin's sandbox fails to restrict alternative file-access methods such as Python's pathlib.Path and io.open. An attacker who can run code under the sandbox simply imports the pathlib or io modules and gains the ability to read and write arbitrary files, completely bypassing the restricted_open file-access controls; the CVSS 4.0 score of 8.7 (High) reflects a network attack vector, no privileges required, and some user interaction. Users running any openssl_encrypt release prior to 1.4.0 to confine untrusted code are affected, since the sandbox can no longer be relied on as a security boundary for filesystem access. Exploitation has not been reported in the wild: the issue is not in CISA KEV, EPSS estimates only a 0.3% chance of exploitation within 30 days, and the sole public reference is the vendor's GitHub security advisory with a proof of concept (GHSA-mcjj-qw7m-j3cp).

What to do: Upgrade to openssl_encrypt 1.4.0 or later, which restricts the alternative file-access methods and restores the sandbox's restricted_open controls. Until patched, do not treat the plugin sandbox as a security boundary for untrusted code, or block imports of the pathlib and io modules where your environment allows import restrictions. Check hosts running the sandbox for unexpected file reads or writes outside the paths permitted by restricted_open.