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Fencer Intel
critical 9.8

CVE-2026-74899 json

openssl_encrypt before 1.4.0 Sandbox Escape via Type Hierarchy

published 9mo ago modified last mo. also EUVD-2026-60116 , GHSA-m25m-ggxg-239c , PYSEC-2026-3727

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

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__.__subclasses__() to access system functions and execute arbitrary OS commands.

Patch / fix

  • pypi openssl-encrypt 1.4.0
  • jahlives openssl_encrypt 1.4.0

Is CVE-2026-74899 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
2mo ago

Exploit prediction

0.75% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-43jx-gxq4-jpjc referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/jahlives/openssl_encrypt/security/advisories/GHSA-m25m-ggxg-239c referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 4.0 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
pypi openssl-encrypt
<1.4.0
1.4.0

Affected products

  • jahlives openssl_encrypt

Classification

Weakness
  • CWE-95 Improper Neutralization of Directives in Dynamically Evaluated Code

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of jahlives/openssl_encrypt published their own advisory on GitHub. Reviewed sources take precedence over it.