CVE-2023-7158Public exploitNetwork attack vector

Interpreter crash via float-to-integer type confusion

Published Dec 29, 2023 · Updated Feb 13, 2025

Heap buffer overflow in MicroPython 1.13.0 through 1.21.0 allows attackers to crash the interpreter with a float slice length. The slice_indices function in py/objslice.c passes the unchecked float object to mp_obj_int_get_checked, which treats the float's layout as an integer and reads beyond its allocation. Reaching the flaw requires executing crafted Python code in the affected runtime; the published proof of concept demonstrates an invalid heap access and interpreter crash.

CVSS severity9.8
Critical
EPSS probability1.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap buffer overflow in MicroPython 1.13.0 through 1.21.0 allows attackers to crash the interpreter with a float slice length. The slice_indices function in py/objslice.c passes the unchecked float object to mp_obj_int_get_checked, which treats the float's layout as an integer and reads beyond its allocation. Reaching the flaw requires executing crafted Python code in the affected runtime; the published proof of concept demonstrates an invalid heap access and interpreter crash.

The record

CVE
CVE-2023-7158
Published
Dec 29, 2023
Updated
Feb 13, 2025
Vendor
MicroPython
Product
MicroPython
Classifications
CWE-122, CWE-787
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 29, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.13.0
  2. Affected versionversion=1.14.0
  3. Affected versionversion=1.15.0
  4. Affected versionversion=1.16.0
  5. Affected versionversion=1.17.0
  6. Affected versionversion=1.18.0
  7. Affected versionversion=1.19.0
  8. Affected versionversion=1.20.0
  9. Affected versionversion=1.21.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MicroPython · MicroPythonversion=1.13.0; version=1.14.0; version=1.15.0; version=1.16.0; version=1.17.0; version=1.18.0; version=1.19.0; version=1.20.0; version=1.21.0

Published CVSS scores

9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CWE-787Out-of-bounds Write

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo