Buffer overflow in Micropython
CVE-2026-1998
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.002 (10.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Micropython
- Micropython — versions 1.0, 1.1, 1.2
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
- vuldb.com/ (Exploit, VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/micropython/micropython/issues/18639 (issue-tracking, Exploit, Issue Tracking)
- github.com/micropython/micropython/pull/18671 (issue-tracking, Exploit, Issue Tracking)
- github.com/micropython/micropython/issues/18639 (issue-tracking, Exploit, exploit, Issue Tracking)
- github.com/dpgeorge/micropython/commit/570744d06c5ba9dba59b4c3f432ca4f0abd396b6 (Patch, patch)
- github.com/micropython/micropython/ (Product, product)
Frequently asked questions
- What is CVE-2026-1998?
- CVE-2026-1998 is a low-severity vulnerability in Micropython, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 3.3/10. Published 2026-02-06.
- How severe is CVE-2026-1998?
- Low severity. CVSS v3 base score is 3.3 out of 10.