---
id: CVE-2026-74899
title: openssl_encrypt before 1.4.0 Sandbox Escape via Type Hierarchy
summary: >-
  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_…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-95
vendor: jahlives
product: openssl_encrypt
affected:
  - openssl_encrypt < 1.4.0
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-08-18T14:40:11.591350Z'
exploitAvailable: true
published: '2026-08-17'
updated: '2026-10-01'
sourceUpdated: '2026-10-01T15:21:05.055Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74899'
references:
  - url: >-
      https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-m25m-ggxg-239c
    label: GitHub Security Advisory (GHSA-m25m-ggxg-239c)
  - url: >-
      https://www.vulncheck.com/advisories/openssl-encrypt-before-sandbox-escape-via-type-hierarchy
    label: >-
      VulnCheck Advisory: openssl_encrypt before 1.4.0 Sandbox Escape via Type
      Hierarchy
  - url: >-
      https://github.com/siyuan-note/siyuan/security/advisories/GHSA-43jx-gxq4-jpjc
tags:
  - cve.org
  - exploit-available
  - osv
  - pip
epss: 0.0075
epssPercentile: 0.54758
aliases:
  - PYSEC-2026-3727
ecosystem: pip
patched:
  - openssl-encrypt 1.4.0
ingestedAt: '2026-08-29T19:29:14.910Z'
---

## Overview

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.

## Affected

- `openssl_encrypt < 1.4.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-74899)

Affected packages:

- `openssl-encrypt < 1.4.0`

Patched in:

- `openssl-encrypt 1.4.0`

Source: https://osv.dev/vulnerability/PYSEC-2026-3727