try/except* clauses could allow bypass RestrictedPython via type confusion bug in the CPython interpreter
RestrictedPython is a tool that helps to define a subset of the Python language which allows to provide a program input into a trusted environment. Via a type confusion bug in versions of the CPython interpreter starting in 3.11 and prior to 3.13.2 when using `try/except*`, RestrictedPython starting in version 6.0 and prior to version 8.0 could be bypassed. The issue is patched in version 8.0 of RestrictedPython by removing support for `try/except*` clauses. No known workarounds are available.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Jan 23, 2025
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 32th percentile
- CWE
- CWE-843
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 7.9
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
zopefoundation RestrictedPython
- >= 6.0, < 8.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:13 | restrictedpython | before 8.0-1 | 8.0-1 |
| PyPI | restrictedpython | from 6.0 · before 8.0 | 8.0 |
Same product
zopefoundation: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-76825RestrictedPython: Sandbox escape via string.Formatter field resolution33Monitor
- CVE-2026-55830RestrictedPython guard hooks can be shadowed via positional-only arguments33Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| zopefoundation RestrictedPython | 8.0 · description | Vendor (CNA) |
| debian:restrictedpython | 8.0-1 · Debian:13 | Package registry (OSV) |
| PyPI:restrictedpython | 8.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- Administrator privileges are required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- low · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- Low
Weakness class (CWE)
CWE-843 · Access of Resource Using Incompatible Type ('Type Confusion')CVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/zopefoundation/RestrictedPython/commit/48a92c5bb617a647cffd0dadd4d5cfe626bcdb2f
- github.com/zopefoundation/RestrictedPython/security/advisories/GHSA-gmj9-h825-chq2
Vendor advisories and official records. Exploit/PoC links are deliberately left out.