Summary
try/except* clauses could allow bypass RestrictedPython via type confusion bug in the CPython interpreter
Workarounds
There is no workaround.
References
none
Impact
Via a type confusion bug in the CPython interpreter when using try/except* RestrictedPython could be bypassed.
We believe this should be fixed upstream in Python itself until that we remove support for try/except* from RestrictedPython.
(It has been fixed for some Python versions.)
An object is accessed using a type that is incompatible with its actual type, causing the runtime to interpret memory incorrectly. Typical impact: memory safety violations, unexpected behavior, or code execution.
CVE-2025-22153 has a CVSS score of 7.9 (High). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (8.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Patched in version 8.0 by removing support for try/except* clauses
Frequently Asked Questions
- What is CVE-2025-22153? CVE-2025-22153 is a high-severity type confusion vulnerability in RestrictedPython (pip), affecting versions >= 6.0, < 8.0. It is fixed in 8.0. An object is accessed using a type that is incompatible with its actual type, causing the runtime to interpret memory incorrectly.
- How severe is CVE-2025-22153? CVE-2025-22153 has a CVSS score of 7.9 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of RestrictedPython are affected by CVE-2025-22153? RestrictedPython (pip) versions >= 6.0, < 8.0 is affected.
- Is there a fix for CVE-2025-22153? Yes. CVE-2025-22153 is fixed in 8.0. Upgrade to this version or later.
- Is CVE-2025-22153 exploitable, and should I be worried? Whether CVE-2025-22153 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-22153 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-22153? Upgrade
RestrictedPythonto 8.0 or later.