What is CVE-2021-35944?

CVE-2021-35944 is a high-severity vulnerability in Couchbase Server, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.5/10. Published 2021-09-29.

How severe is CVE-2021-35944?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Couchbase Server

CVE-2021-35944

Couchbase Server 6.5.x, 6.6.x through 6.6.2, and 7.0.0 has a Buffer Overflow. A specially crafted network packet sent from an attacker can crash memcached.

Vulnerability class: Buffer Overflow

Published 2021-09-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.011 (64.1th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 64th percentile — 64.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.011 · newest: 0.011 · change: 0.000

Affected products

Couchbase Server — versions 7.0.0

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

docs.couchbase.com/server/current/release-notes/relnotes.html (Release Notes, Vendor Advisory)
www.couchbase.com/alerts (Vendor Advisory)

Frequently asked questions

What is CVE-2021-35944?: CVE-2021-35944 is a high-severity vulnerability in Couchbase Server, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.5/10. Published 2021-09-29.
How severe is CVE-2021-35944?: High severity. CVSS v3 base score is 7.5 out of 10.