What is CVE-2019-6471?

CVE-2019-6471 is a medium-severity vulnerability in F5 Big-Ip Access Policy Manager, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 5.9/10. Published 2019-10-09.

How severe is CVE-2019-6471?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Is CVE-2019-6471 known to be exploited?

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

Vulnerability in F5 Big-Ip Access Policy Manager

CVE-2019-6471

A race condition which may occur when discarding malformed packets can result in BIND exiting due to a REQUIRE assertion failure in dispatch.c. Versions affected: BIND 9.11.0 -> 9.11.7, 9.12.0 -> 9.12.4-P1, 9.14.0 -> 9.14.2. Also all releases of the BIND 9.13 development branch and version 9.15.0 of the BIND 9.15 development branch and BIND Supported Preview Edition versions 9.11.3-S1 -> 9.11.7-S1.

Vulnerability class: Race Condition

Published 2019-10-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.033 (88.1th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.033 · newest: 0.033 · change: 0.000

Affected products

F5 Big-Ip Access Policy Manager — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Advanced Firewall Manager — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Analytics — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Application Acceleration Manager — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Application Security Manager — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Domain Name System — versions 9.2.2, 14.0.0, 14.1.0
F5 Big-Ip Edge Gateway — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Fraud Protection Service — versions 14.0.0, 14.1.0, 15.0.0
F5 Big-Ip Global Traffic Manager — versions 9.2.2, 14.0.0, 14.1.0
F5 Big-Ip Link Controller — versions 9.2.2, 14.0.0, 14.1.0

Weakness classification (CWE)

Public proof-of-concept exploits

References

kb.isc.org/docs/cve-2019-6471 (Third Party Advisory)
support.f5.com/csp/article/K10092301

Frequently asked questions

What is CVE-2019-6471?: CVE-2019-6471 is a medium-severity vulnerability in F5 Big-Ip Access Policy Manager, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 5.9/10. Published 2019-10-09.
How severe is CVE-2019-6471?: Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2019-6471 known to be exploited?: 9 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.