What is CVE-2021-37519?

CVE-2021-37519 is a medium-severity vulnerability in Memcached, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2023-02-03.

How severe is CVE-2021-37519?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Memcached

CVE-2021-37519

Buffer Overflow vulnerability in authfile.c memcached 1.6.9 allows attackers to cause a denial of service via crafted authenticattion file.

Vulnerability class: Buffer Overflow

Published 2023-02-03 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (27.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Memcached — versions 1.6.9

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/memcached/memcached/issues/805 (Exploit, Third Party Advisory, Issue Tracking)
github.com/memcached/memcached/pull/806/commits/264722ae4e248b453be00e97197dadc… (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-37519?: CVE-2021-37519 is a medium-severity vulnerability in Memcached, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2023-02-03.
How severe is CVE-2021-37519?: Medium severity. CVSS v3 base score is 5.5 out of 10.