What is CVE-2026-21384?

CVE-2026-21384 is a medium-severity vulnerability in Qualcomm Fastconnect 6700, classified under Out-of-bounds Write. CVSS score: 5.3/10. Published 2026-07-06.

How severe is CVE-2026-21384?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Buffer overflow in Qualcomm Fastconnect 6700

CVE-2026-21384

Memory Corruption when updating prepared commands with invalid port indices based on user space input exceeds supported read client limits.

Vulnerability class: Buffer Overflow

Published 2026-07-06 · last modified 2026-07-07.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.001 (0.1th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 0th percentile — 0.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

docs.qualcomm.com/product/publicresources/securitybulletin/july-2026-bulletin.h… (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21384?: CVE-2026-21384 is a medium-severity vulnerability in Qualcomm Fastconnect 6700, classified under Out-of-bounds Write. CVSS score: 5.3/10. Published 2026-07-06.
How severe is CVE-2026-21384?: Medium severity. CVSS v3 base score is 5.3 out of 10.