PatchTheCVECVE-2026-74899: openssl_encrypt versions before 1.4.0 contain a sandbox escape vulnerability in IsolatedPluginExecutor that ex
CVE-2026-74899 is a critical-severity flaw (CVSS 9.8) affecting openssl encrypt. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- Critical severity
- Public exploit reference
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.8% (top 45%) |
| CISA exploited list | No |
| Weakness | CWE-95 |
| Published | 2026-08-17 |
| Last modified | 2026-08-28 |
Last updated 2026-08-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Public exploits and detection
Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.
- Write-up: github.com/jahlives/openssl_encrypt/security/advisories/GHSA-m25m-ggxg-239c
- Write-up: github.com/siyuan-note/siyuan/security/advisories/GHSA-43jx-gxq4-jpjc
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-74899?
openssl encrypt: upgrade to 1.4.0. Exact commands for each OS are on this page.
Is CVE-2026-74899 being exploited?
CVE-2026-74899 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-74899 affect?
CVE-2026-74899 affects openssl encrypt. Severity is critical (CVSS 9.8). 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__._
How urgent is CVE-2026-74899?
Priority 66/100. Critical severity; Public exploit reference; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist
Software pages
OpenSSL vulnerabilities · Python vulnerabilities
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