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NVD / CVE Program· CNA VulDB

CVE-2023-7158: MicroPython objslice.c slice_indices heap-based overflow

Noroxi assessment

Priority: Monitor (action score 39/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.2% (FIRST EPSS); higher than 68.8% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: n/a MicroPython 1.22.0.
  • Severity is disputed: the assigning authority (CNA) scores it 7.3, NVD 9.8.

Low priority for now. Upgrade to n/a MicroPython 1.22.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability was found in MicroPython up to 1.21.0. It has been classified as critical. Affected is the function slice_indices of the file objslice.c. The manipulation leads to heap-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 1.22.0 is able to address this issue. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-249180.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Dec 29, 2023
Updated
Jun 17, 2026
EPSS
1.2% · 68th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.2%

CNA vs NVD score

NVD
9.8
CNA · VulDB
7.3
2.5 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
micropythonmicropython

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • micropython micropythonbefore 1.22.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a MicroPython

    • 1.13.0, 1.14.0, 1.15.0, 1.16.0, 1.17.0, 1.18.0, 1.19.0, 1.20.0, 1.21.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
openSUSE:Tumbleweedmicropythonbefore 1.22.0-1.11.22.0-1.1

Same product

micropython: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-7152MicroPython modselect.c poll_set_add_fd use after free
    39Monitor
  • CVE-2024-8948MicroPython objint.c mpz_as_bytes heap-based overflow
    27Monitor
  • CVE-2024-8946MicroPython VFS Unmount vfs.c mp_vfs_umount heap-based overflow
    27Monitor

Published before and after this one in the same product

  • Later →CVE-2024-8947Sep 17, 2024 · MicroPython objarray.c use after free
    25Monitor
  • Later →CVE-2026-1998Feb 6, 2026 · micropython runtime.c mp_import_all memory corruption
    7Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
n/a MicroPython1.22.0 · descriptionVendor (CNA)
opensuse:micropython1.22.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2024-8946263 days apartMicroPython VFS Unmount vfs.c mp_vfs_umount heap-based overflow
    27Monitor
  • CVE-2024-8948263 days apartMicroPython objint.c mpz_as_bytes heap-based overflow
    27Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-122 · Heap-based Buffer Overflow

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records