Information disclosure in Zopefoundation Restrictedpython

CVE-2026-76825

RestrictedPython is a tool that helps define a subset of the Python language for accepting program input in a trusted environment. Prior to 8.4, RestrictedPython could allow a sandbox escape when a custom import policy or globals exposed the standard library string module, the string.Formatter class, a Formatter instance, or a Formatter subclass to restricted code. The string.Formatter methods format, get_field, get_value, and vformat performed attribute and item traversal internally without passing through RestrictedPython's safer_getattr protections. Restricted code could use those live object references to reach function globals, builtins, file access, or code execution primitives, affecting confidentiality, integrity, and availability in the host environment. This issue is fixed in version 8.4.

Vulnerability class: Information Disclosure

CVSS v3 metric

CVSS v3 base score 8.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-76825?
CVE-2026-76825 is a high-severity vulnerability in Zopefoundation Restrictedpython, classified under Information Disclosure. CVSS score: 8.4/10. Published 2026-09-16.
How severe is CVE-2026-76825?
High severity. CVSS v3 base score is 8.4 out of 10.