What is CVE-2019-6476?

CVE-2019-6476 is a medium-severity vulnerability in Isc Bind, classified under Reachable Assertion. CVSS score: 5.9/10. Published 2019-10-17.

How severe is CVE-2019-6476?

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

Is CVE-2019-6476 known to be exploited?

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

Vulnerability in Isc Bind

CVE-2019-6476

A defect in code added to support QNAME minimization can cause named to exit with an assertion failure if a forwarder returns a referral rather than resolving the query. This affects BIND versions 9.14.0 up to 9.14.6, and 9.15.0 up to 9.15.4.

Published 2019-10-17 · 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: 0.029 (86.4th percentile), scored 2026-09-28.

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 86.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.029 · newest: 0.029 · change: 0.000

Affected products

Isc Bind
Isc Bind 9 — versions 9.14.0 up to 9.14.6, 9.15.0 up to 9.15.4

Weakness classification (CWE)

CWE-617 — Reachable Assertion

Public proof-of-concept exploits

bg6cq/bind9

References

kb.isc.org/docs/cve-2019-6476 (Third Party Advisory)
security.netapp.com/advisory/ntap-20191024-0004/
support.f5.com/csp/article/K42238532

Frequently asked questions

What is CVE-2019-6476?: CVE-2019-6476 is a medium-severity vulnerability in Isc Bind, classified under Reachable Assertion. CVSS score: 5.9/10. Published 2019-10-17.
How severe is CVE-2019-6476?: Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2019-6476 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.