CVE-2026-74899 openssl_encrypt before 1.4.0 Sandbox Escape via Type Hierarchy

Critical 9.3 Published 17 Aug 2026 Updated 1 Oct 2026

Attackers can escape the sandbox in openssl_encrypt to execute arbitrary OS commands by traversing Python type hierarchies.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-74899?

CVE-2026-74899 is a critical code injection vulnerability in Jahlives Openssl Encrypt, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

openssl_encrypt versions before 1.4.0 contain a sandbox escape vulnerability in IsolatedPluginExecutor that exposes Python type objects in restricted exec() builtins. Attackers can traverse the Python class hierarchy via __class__.__mro__.__subclasses__() to access system functions and execute arbitrary OS commands.

Weakness: CWE-95

Which versions are affected by CVE-2026-74899?

1 open source package ship an affected version, including openssl-encrypt. It affects 1 product.

Package	Affected	Fixed in
`openssl-encrypt` PyPI	All versions	`1.4.0`

Products include Jahlives Openssl Encrypt.

How do I fix CVE-2026-74899?

Upgrade openssl-encrypt to 1.4.0 or later.

Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.

Is CVE-2026-74899 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-74899 exists.

All Jahlives Openssl Encrypt vulnerabilities

Sources

Also known as GHSA-5cp4-g2w4-gm8p, PYSEC-2026-3727.