CVE-2026-1998VulnerabilityPublished 6 Feb 2026Updated 23 Feb 2026

CVE-2026-1998: micropython · Memory Corruption

Affects micropythonSource CVE Database V5

Not known to be exploited · CVSS 4.8 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

4.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS: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

Base metrics

Attack Vector: Local
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the Vulnerable System are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
micropython	Affected =1.0 =1.1 =1.2 =1.3 =1.4 =1.5 =1.6 =1.7 =1.8 =1.9 =1.10 =1.11 =1.12 =1.13 =1.14 =1.15 =1.16 =1.17 =1.18 =1.19 =1.20 =1.21 =1.22 =1.23 =1.24 =1.25 =1.26 =1.27.0	Fixed in–
GitHubmicropython/micropython`pkg:github/micropython/micropython`Other threats	Affected =1.0 =1.1 =1.2 =1.3 =1.4 =1.5 =1.6 =1.7 =1.8 =1.9 =1.10 =1.11 =1.12 =1.13 =1.14 =1.15 =1.16 =1.17 =1.18 =1.19 =1.20 =1.21 =1.22 =1.23 =1.24 =1.25 =1.26 =1.27.0	Fixed in–

CPE configurations (1)

cpe:2.3:a:micropython:micropython:*:*:*:*:*:*:*:*

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should immediately apply the official patch released for micropython, identified by commit 570744d06c5ba9dba59b4c3f432ca4f0abd396b6, to remediate the vulnerability. Beyond patching, it is critical to restrict local access to devices running micropython by enforcing strict access controls and monitoring for unauthorized access attempts. Implementing robust endpoint security measures on devices can help detect and prevent exploitation attempts. Regularly auditing and updating embedded device firmware and software will reduce exposure to known vulnerabilities. For environments where patching is delayed, consider isolating affected devices from critical networks to limit potential impact. Additionally, employing runtime protections such as memory safety tools or sandboxing micropython processes can mitigate exploitation risks. Organizations should also educate personnel about the risks of local attacks and ensure that devices are physically secured to prevent unauthorized local access.

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.

Impact

The primary impact of this vulnerability is memory corruption, which can lead to application crashes, denial of service, or potentially arbitrary code execution if exploited successfully. Since the attack requires local access with limited privileges, the threat is mainly from insiders or attackers who have already compromised the device to some extent. For embedded systems and IoT devices running micropython, exploitation could disrupt device functionality or be leveraged as a stepping stone for further attacks within a network. This could affect operational continuity, data integrity, and potentially confidentiality if attackers escalate privileges. Given micropython's use in various embedded applications worldwide, the vulnerability could impact industries relying on these devices, including manufacturing, healthcare, and smart infrastructure. However, the lack of remote exploitability and user interaction requirement limits the scope and ease of exploitation, reducing the overall risk compared to remote vulnerabilities.

References

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