What is CVE-2021-40154?

CVE-2021-40154 is a medium-severity vulnerability in Nxp Lpc55s69jbd100, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2021-12-01.

How severe is CVE-2021-40154?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2021-40154 known to be exploited?

5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Out-of-bounds Read in Nxp Lpc55s69jbd100

CVE-2021-40154

NXP LPC55S69 devices before A3 have a buffer over-read via a crafted wlength value in a GET Descriptor Configuration request during use of USB In-System Programming (ISP) mode. This discloses protected flash memory.

Vulnerability class: Buffer Overflow

Published 2021-12-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L.

EPSS exploit prediction

EPSS: 0.008 (53.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 53.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.008 · change: +0.000

Affected products

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

Public proof-of-concept exploits

References

www.darkmatter.ae/xen1thlabs/published-advisories/ (Third Party Advisory, Broken Link)
github.com/Xen1thLabs-AE/CVE-2021-40154 (Third Party Advisory)

Frequently asked questions

What is CVE-2021-40154?: CVE-2021-40154 is a medium-severity vulnerability in Nxp Lpc55s69jbd100, classified under Out-of-bounds Read. CVSS score: 6.1/10. Published 2021-12-01.
How severe is CVE-2021-40154?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2021-40154 known to be exploited?: 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.