CVE-2026-11721

MEDIUM

7.5

CVSS v3

Description

It is possible for an attacker's zone to respond to a query with an RRSIG that has a smaller number of labels than the zone in which the RRSIG is contained. This causes `named` to produce a wildcard name for a zone that is shorter than the attacker's zone, which can result in cache poisoning. For this attack to have any effect, the resolver under attack must have set `synth-from-dnssec yes;` (which is the default). This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

CWE-1284

How to fix

Remediation Available

bind9Debian

Fixed in:1:9.16.50-1~deb11u6CVE-2026-11721

Fixed in:1:9.18.49-1~deb12u2CVE-2026-11721

Fixed in:1:9.20.26-1~deb13u1CVE-2026-11721

Fixed in:1:9.20.26-1CVE-2026-11721

bindRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

bindRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

bind-chrootRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

bind-chrootRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

bind-debuginfoRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

bind-debuginfoRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

bind-debugsourceRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-debugsourceRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-develRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

bind-develRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

bind-dnssec-docRocky

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

bind-dnssec-docRed Hat / RHEL

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

bind-dnssec-utilsRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

bind-dnssec-utilsRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

bind-dnssec-utils-debuginfoRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

bind-dnssec-utils-debuginfoRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

Fixed in:32:9.16.23-18.el9_4.12RHSA-2026:57189

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

bind-docRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

bind-docRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.16.23-40.el9_8.8RHSA-2026:54510

Fixed in:32:9.16.23-31.el9_6.4RHSA-2026:55441

bind-export-develRed Hat / RHEL

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-export-develRocky

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-export-libsRocky

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-export-libsRed Hat / RHEL

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-export-libs-debuginfoRed Hat / RHEL

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-export-libs-debuginfoRocky

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-libsRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

bind-libsRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

bind-libs-debuginfoRed Hat / RHEL

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-libs-debuginfoRocky

Fixed in:32:9.18.33-15.el10_2.10RHSA-2026:55437

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

bind-libs-liteRocky

Fixed in:32:9.11.4-26.P2.el7_9.21.ppcRHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.ppc64RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21.s390RHSA-2026:60383

Fixed in:32:9.11.4-26.P2.el7_9.21RHSA-2026:60383

Fixed in:32:9.11.36-16.el8_10.14RHSA-2026:54654

This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U

Exploit Intelligence

0.40%probability of exploitation in 30 days

33rdpercentile

Low risk: more likely to be exploited than 33% of all known CVEs.

References

Other references3

Related Vulnerabilities

Other CWE-1284 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2022-20699	Critical	10.0	72%	KEV	-
CVE-2021-43267	Critical	9.8	58%	-	Fix
CVE-2022-31629	Medium	6.5	49%	-	Fix
CVE-2025-9316	Unscored	-	36%	-	-
CVE-2022-36620	High	7.5	23%	-	-
CVE-2008-1440	High	7.1	23%	-	-

Common questions

How do I fix CVE-2026-11721?

Published advisories record a fix for 124 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-11721 being actively exploited?

Not that we know of. CVE-2026-11721 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.40% is the estimated probability that it will be exploited in the next 30 days. That is higher than 33% of all scored CVEs.

How severe is CVE-2026-11721?

CVE-2026-11721 has a CVSS v3 base score of 7.5, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-11721 affect?

Published advisories record a fix for bind9 (Debian), bind (Rocky), bind (Red Hat / RHEL), bind-chroot (Red Hat / RHEL), and 120 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-11721

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-22.