What is CVE-2019-11934?

CVE-2019-11934 is a critical-severity vulnerability in Facebook Folly, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2019-12-04.

How severe is CVE-2019-11934?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Out-of-bounds Read in Facebook Folly

CVE-2019-11934

Improper handling of close_notify alerts can result in an out-of-bounds read in AsyncSSLSocket. This issue affects folly prior to v2019.11.04.00.

Vulnerability class: Buffer Overflow

Published 2019-12-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.017 (76.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 77th percentile — 76.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: 0.000

Affected products

Facebook Folly — versions v2019.11.04.00, unspecified

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

github.com/facebook/folly/commit/c321eb588909646c15aefde035fd3133ba32cdee (Patch, Third Party Advisory)
www.facebook.com/security/advisories/cve-2019-11934 (Third Party Advisory)

Frequently asked questions

What is CVE-2019-11934?: CVE-2019-11934 is a critical-severity vulnerability in Facebook Folly, classified under Out-of-bounds Read. CVSS score: 9.8/10. Published 2019-12-04.
How severe is CVE-2019-11934?: Critical severity. CVSS v3 base score is 9.8 out of 10.