CVE-2026-76825RestrictedPython: Sandbox escape via string.Formatter field resolution
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No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 8.4 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-200, CWE-470, CWE-680, CWE-693
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Deferred
- Record last updated
- Sep 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
zopefoundation RestrictedPython zopefoundation:restrictedpython (from the name) | before 8.4 | CNA record |
References
- https://github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-hp3v-5vw7-fx9wx-refsource-confirm
- https://github.com/zopefoundation/RestrictedPython/commit/3b47440070b91f8807c2b2998aca99e94783639ax-refsource-misc
- https://github.com/zopefoundation/RestrictedPython/releases/tag/8.4x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.