CVE-2026-1998Public exploit

Runtime crash via non-module import-star handling

Published Feb 6, 2026 · Updated Feb 6, 2026

Memory corruption in MicroPython 1.27.0 and earlier allows local users to crash the runtime through a crafted import-star operation. The mp_import_all function treats its source as a native module and passes an invalid globals map to mp_map_lookup when a custom importer returns a class. A local user who can run a crafted script can terminate the interpreter process or reset an attached device; no code execution or data access is reported.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in MicroPython 1.27.0 and earlier allows local users to crash the runtime through a crafted import-star operation. The mp_import_all function treats its source as a native module and passes an invalid globals map to mp_map_lookup when a custom importer returns a class. A local user who can run a crafted script can terminate the interpreter process or reset an attached device; no code execution or data access is reported.

The record

CVE
CVE-2026-1998
Published
Feb 6, 2026
Updated
Feb 6, 2026
Vendor
MicroPython
Product
MicroPython
Classifications
CWE-119, CWE-787, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 6, 2026Record 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=1.0
  2. Affected versionversion=1.1
  3. Affected versionversion=1.10
  4. Affected versionversion=1.11
  5. Affected versionversion=1.12
  6. Affected versionversion=1.13
  7. Affected versionversion=1.14
  8. Affected versionversion=1.15
  9. Affected versionversion=1.16
  10. Affected versionversion=1.17
  11. Affected versionversion=1.18
  12. Affected versionversion=1.19
  13. Affected versionversion=1.2
  14. Affected versionversion=1.20
  15. Affected versionversion=1.21
  16. Affected versionversion=1.22
  17. Affected versionversion=1.23
  18. Affected versionversion=1.24
  19. Affected versionversion=1.25
  20. Affected versionversion=1.26
  21. Affected versionversion=1.27.0
  22. Affected versionversion=1.3
  23. Affected versionversion=1.4
  24. Affected versionversion=1.5
  25. Affected versionversion=1.6
  26. Affected versionversion=1.7
  27. Affected versionversion=1.8
  28. Affected versionversion=1.9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

MicroPython · MicroPythonversion=1.0; version=1.1; version=1.10; version=1.11; version=1.12; version=1.13; version=1.14; version=1.15; version=1.16; version=1.17; version=1.18; version=1.19; version=1.2; version=1.20; version=1.21; version=1.22; version=1.23; version=1.24; version=1.25; version=1.26; version=1.27.0; version=1.3; version=1.4; version=1.5; version=1.6; version=1.7; version=1.8; version=1.9

Published CVSS scores

3.3VulDBCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
1.9VulDBCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
1.7VulDBAV:L/AC:L/Au:S/C:N/I:N/A:P

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.

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No observations available

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

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

Public exploit references

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

Technologies

Your stack

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Your stack

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