CVE-2026-1998: micropython runtime.c mp_import_all memory corruption

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-02-06 · updated 2026-06-17
Weakness: CWE-119

Description

A flaw has been found in micropython up to 1.27.0. This vulnerability affects the function mp_import_all of the file py/runtime.c. This manipulation causes memory corruption. The attack needs to be launched locally. The exploit has been published and may be used. Patch name: 570744d06c5ba9dba59b4c3f432ca4f0abd396b6. It is suggested to install a patch to address this issue.

Affected products

MicroPython: through 1.27.0

References

https://github.com/dpgeorge/micropython/commit/570744d06c5ba9dba59b4c3f432ca4f0abd396b6
https://github.com/micropython/micropython/
https://github.com/micropython/micropython/issues/18639
https://github.com/micropython/micropython/issues/18639#issue-3780651410
https://github.com/micropython/micropython/pull/18671
https://vuldb.com/?ctiid.344546
https://vuldb.com/?id.344546
https://vuldb.com/?submit.743396

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