CVE-2016-9778 [High] | Security Vulnerability in Bind

An error in handling certain queries can cause an assertion failure when a server is using the nxdomain-redirect feature to cover a zone for which it is also providing authoritative service. A vulnerable server could be intentionally stopped by an attacker if it was using a configuration that met the criteria for the vulnerability and if the attacker could cause it to accept a query that possessed the required attributes. Please note: This vulnerability affects the "nxdomain-redirect" feature, which is one of two methods of handling NXDOMAIN redirection, and is only available in certain versions of BIND. Redirection using zones of type "redirect" is not affected by this vulnerability. Affects BIND 9.9.8-S1 -> 9.9.8-S3, 9.9.9-S1 -> 9.9.9-S6, 9.11.0-9.11.0-P1.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	5.42%	12.00%	+6.58%
2	2026-04-15	6.61%	5.42%	-1.19%
3	2026-02-03	—	6.61%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

5.42%

12.00%

+6.58%

2026-04-15

6.61%

5.42%

-1.19%

2026-02-03

—

6.61%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.0	HIGH	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	3.6	[email protected]
5.9	3.0	MEDIUM	`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	2.2	3.6	[email protected]
4.3	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:N/I:N/A:P` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	8.6	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.0

HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

3.6

[email protected]

5.9

3.0

MEDIUM

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

2.2

3.6

[email protected]

4.3

2.0

MEDIUM

AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

8.6

2.9

[email protected]

OS Trackers for CVE-2016-9778

vendor	priority	summary	link
`debian`	unimportant	CVE-2016-9778 unimportant priority: Debian including 1 source packages (bind9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2016-9778
`gentoo`	normal	CVE-2016-9778: 1 GLSA(s) (201708-01), 1 atom(s) (net-dns/bind); latest impact normal.	https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-9778
`redhat`	high	—	https://access.redhat.com/security/cve/CVE-2016-9778
`suse`	high	CVE-2016-9778 severity important: SUSE including 365 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 486 product×package rows across 34 product lines (SUSE CaaS Platform 4.0, SUSE Enterprise Storage 6, … (34 product lines)): Fixed 207, Known Affected 157, Known Not Affected 122.	https://www.suse.com/security/cve/CVE-2016-9778/
`ubuntu`	medium	CVE-2016-9778 medium priority: Ubuntu including 1 source packages (bind9), 5 status rows across 5 suites (precise, trusty, upstream, xenial, yakkety): not-affected 4, needs-triage 1.	https://ubuntu.com/security/CVE-2016-9778

Affected software / configurations for CVE-2016-9778

Vendor	Product	Version	Raw CPE
isc	bind	9.9.8	cpe:2.3:a:isc:bind:9.9.8:s1::::::
isc	bind	9.9.8	cpe:2.3:a:isc:bind:9.9.8:s2::::::
isc	bind	9.9.8	cpe:2.3:a:isc:bind:9.9.8:s3::::::
isc	bind	9.9.9	cpe:2.3:a:isc:bind:9.9.9:s1::::::
isc	bind	9.9.9	cpe:2.3:a:isc:bind:9.9.9:s6::::::
isc	bind	9.11.0	cpe:2.3:a:isc:bind:9.11.0:::::::*
isc	bind	9.11.0	cpe:2.3:a:isc:bind:9.11.0:p1::::::
netapp	data_ontap_edge	—	cpe:2.3:a:netapp:data_ontap_edge:-:::::::*
netapp	solidfire_element_os_management_node	—	cpe:2.3:a:netapp:solidfire_element_os_management_node:-:::::::*

References for CVE-2016-9778

URL	Tags
http://www.securityfocus.com/bid/95388	Third Party Advisory VDB Entry
http://www.securitytracker.com/id/1037582	Third Party Advisory VDB Entry
https://kb.isc.org/article/AA-01442/	Vendor Advisory
https://security.gentoo.org/glsa/201708-01	Third Party Advisory
https://security.netapp.com/advisory/ntap-20180926-0005/	Third Party Advisory

URL

CVE-2016-9778 | An error handling certain queries using the nxdomain-redirect feature could cause a REQUIRE assertion failure in db.c

Exploit prediction scoring system (EPSS) score for CVE-2016-9778

Common vulnerability scoring system (CVSS) metrics for CVE-2016-9778

Weakness enumeration for CVE-2016-9778

OS Trackers for CVE-2016-9778

Affected software / configurations for CVE-2016-9778

References for CVE-2016-9778