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TI-2026-10125 Aliases CVE-2026-11721GHSA-cq66-h8mj-77hh

Cache poisoning possible with label count discrepancy, RRSIG, and wildcards

Priority LOW 39CWE-1284Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 29 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00395 33rd percentileScored 2026-11-07
Fix Partial Red Hat: 20 advisoriesRed Hat: 29 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ISCBIND 99.11.0 – 9.18.50; 9.20.0 – 9.20.24; 9.21.0 – 9.21.23; 9.11.3-S1 – 9.18.50-S1; 9.20.9-S1 – 9.20.24-S1—No fix listedCNA
  • BIND 9 VendorISC Affected 9.11.0 – 9.18.50; 9.20.0 – 9.20.24; 9.21.0 – 9.21.23; 9.11.3-S1 – 9.18.50-S1; 9.20.9-S1 – 9.20.24-S1 Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*9.11.0 – 9.18.50VulnerableISC
cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:*9.11.3 – 9.18.50VulnerableISC
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*9.20.0 – 9.20.24VulnerableISC
cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:*9.20.9 – 9.20.24VulnerableISC
cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*9.21.0 – 9.21.23VulnerableISC
  • cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* Versions 9.11.0 – 9.18.50 Vulnerable ·ISC
  • cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* Versions 9.11.3 – 9.18.50 Vulnerable ·ISC
  • cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* Versions 9.20.0 – 9.20.24 Vulnerable ·ISC
  • cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* Versions 9.20.9 – 9.20.24 Vulnerable ·ISC
  • cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* Versions 9.21.0 – 9.21.23 Vulnerable ·ISC

Remediation

Red Hat 20 advisories

  • RHSA-2026:95727 Released 2026-11-06 · Red Hat rating Important
    bind security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION) bind-32:9.8.2-0.68.rc1.el6_10.20, bind-libs-32:9.8.2-0.68.rc1.el6_10.20
    • Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION) bind-sdb-32:9.8.2-0.68.rc1.el6_10.20
  • RHSA-2026:95477 Released 2026-11-05 · Red Hat rating Important
    bind security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream AUS (v.8.4) bind-32:9.11.26-4.el8_4.10, bind-libs-32:9.11.26-4.el8_4.10, bind-libs-lite-32:9.11.26-4.el8_4.10 +5
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) bind-32:9.11.26-4.el8_4.10, bind-libs-32:9.11.26-4.el8_4.10, bind-libs-lite-32:9.11.26-4.el8_4.10 +5
    • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bind-32:9.11.26-4.el8_4.10, bind-export-libs-32:9.11.26-4.el8_4.10
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bind-32:9.11.26-4.el8_4.10, bind-export-libs-32:9.11.26-4.el8_4.10
  • RHSA-2026:95478 Released 2026-11-05 · Red Hat rating Important
    bind security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) bind-32:9.11.36-8.el8_8.11, bind-libs-lite-32:9.11.36-8.el8_8.11, bind-pkcs11-32:9.11.36-8.el8_8.11 +4
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) bind-32:9.11.36-8.el8_8.11, bind-libs-lite-32:9.11.36-8.el8_8.11, bind-pkcs11-32:9.11.36-8.el8_8.11 +4
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bind-32:9.11.36-8.el8_8.11, bind-export-libs-32:9.11.36-8.el8_8.11
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bind-32:9.11.36-8.el8_8.11, bind-export-libs-32:9.11.36-8.el8_8.11
Show 17 more Red Hat advisories
  • RHSA-2026:95435 Released 2026-11-05 · Red Hat rating Important
    bind security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) bind-32:9.11.36-3.el8_6.13, bind-chroot-32:9.11.36-3.el8_6.13, bind-devel-32:9.11.36-3.el8_6.13 +12
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) bind-32:9.11.36-3.el8_6.13, bind-chroot-32:9.11.36-3.el8_6.13, bind-devel-32:9.11.36-3.el8_6.13 +12
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bind-32:9.11.36-3.el8_6.13, bind-export-devel-32:9.11.36-3.el8_6.13, bind-export-libs-32:9.11.36-3.el8_6.13
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bind-32:9.11.36-3.el8_6.13, bind-export-devel-32:9.11.36-3.el8_6.13, bind-export-libs-32:9.11.36-3.el8_6.13
  • RHSA-2026:95242 Released 2026-11-04 · Red Hat rating Important
    bind security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) bind-32:9.16.23-11.el9_2.12, bind-dnssec-utils-32:9.16.23-11.el9_2.12, bind-libs-32:9.16.23-11.el9_2.12
  • RHSA-2026:94278 Released 2026-11-03 · Red Hat rating Important
    bind9.18 security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) bind9.18-libs-32:9.18.29-4.el9_6.5
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) bind9.18-32:9.18.29-4.el9_6.5, bind9.18-dnssec-utils-32:9.18.29-4.el9_6.5, bind9.18-libs-32:9.18.29-4.el9_6.5
  • RHSA-2026:94115 Released 2026-11-03 · Red Hat rating Important
    bind security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) bind-32:9.18.33-4.el10_0.6, bind-dnssec-utils-32:9.18.33-4.el10_0.6, bind-libs-32:9.18.33-4.el10_0.6
  • RHSA-2026:80501 Released 2026-10-12 · Red Hat rating Important
    bind9.16 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream AUS (v.8.6) bind9.16-32:9.16.23-0.7.el8_6.11, bind9.16-libs-32:9.16.23-0.7.el8_6.11
    • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) bind9.16-32:9.16.23-0.7.el8_6.11, bind9.16-libs-32:9.16.23-0.7.el8_6.11
  • RHSA-2026:79160 Released 2026-10-08 · Red Hat rating Important
    bind9.16 security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.8.8) bind9.16-32:9.16.23-0.14.el8_8.9, bind9.16-dnssec-utils-32:9.16.23-0.14.el8_8.9, bind9.16-libs-32:9.16.23-0.14.el8_8.9
    • Red Hat Enterprise Linux AppStream TUS (v.8.8) bind9.16-32:9.16.23-0.14.el8_8.9, bind9.16-dnssec-utils-32:9.16.23-0.14.el8_8.9, bind9.16-libs-32:9.16.23-0.14.el8_8.9
  • RHSA-2026:66357 Released 2026-09-15 · Red Hat rating Important
    OpenShift Container Platform 4.22.14 bug fix and security update
    • Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202609081748-0, rhcos-ppc64le-4.22.9.8.202609081748-0, rhcos-s390x-4.22.9.8.202609081748-0 +1
  • RHSA-2026:60383 Released 2026-08-26 · Red Hat rating Important
    bind security update
    • Red Hat Enterprise Linux Server (v. 7 ELS) bind-32:9.11.4-26.P2.el7_9.21, bind-export-libs-32:9.11.4-26.P2.el7_9.21, bind-export-libs-32:9.11.4-26.P2.el7_9.21.ppc +6
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) bind-sdb-32:9.11.4-26.P2.el7_9.21
  • RHSA-2026:57362 Released 2026-08-25 · Red Hat rating Important
    OpenShift Container Platform 4.22.11 bug fix and security update
    • Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202608191915-0, rhcos-ppc64le-4.22.9.8.202608191915-0, rhcos-s390x-4.22.9.8.202608191915-0 +1
  • RHSA-2026:57189 Released 2026-08-19 · Red Hat rating Important
    bind security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) bind-32:9.16.23-18.el9_4.12, bind-chroot-32:9.16.23-18.el9_4.12, bind-dnssec-doc-32:9.16.23-18.el9_4.12 +5
  • RHSA-2026:55442 Released 2026-08-17 · Red Hat rating Important
    bind9.18 security update
    • Red Hat Enterprise Linux AppStream (v. 9) bind9.18-32:9.18.29-14.el9_8.8, bind9.18-chroot-32:9.18.29-14.el9_8.8, bind9.18-dnssec-utils-32:9.18.29-14.el9_8.8 +2
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) bind9.18-devel-32:9.18.29-14.el9_8.8, bind9.18-doc-32:9.18.29-14.el9_8.8, bind9.18-libs-32:9.18.29-14.el9_8.8
  • RHSA-2026:55437 Released 2026-08-17 · Red Hat rating Important
    bind security update
    • Red Hat Enterprise Linux AppStream (v. 10) bind-32:9.18.33-15.el10_2.10, bind-chroot-32:9.18.33-15.el10_2.10, bind-dnssec-utils-32:9.18.33-15.el10_2.10 +3
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) bind-devel-32:9.18.33-15.el10_2.10, bind-doc-32:9.18.33-15.el10_2.10
  • RHSA-2026:55441 Released 2026-08-17 · Red Hat rating Important
    bind security update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) bind-libs-32:9.16.23-31.el9_6.4
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) bind-32:9.16.23-31.el9_6.4, bind-dnssec-utils-32:9.16.23-31.el9_6.4, bind-libs-32:9.16.23-31.el9_6.4 +1
  • RHSA-2026:54654 Released 2026-08-13 · Red Hat rating Important
    bind security update
    • Red Hat Enterprise Linux AppStream (v. 8) bind-32:9.11.36-16.el8_10.14, bind-chroot-32:9.11.36-16.el8_10.14, bind-devel-32:9.11.36-16.el8_10.14 +12
    • Red Hat Enterprise Linux BaseOS (v. 8) bind-32:9.11.36-16.el8_10.14, bind-export-devel-32:9.11.36-16.el8_10.14, bind-export-libs-32:9.11.36-16.el8_10.14
  • RHSA-2026:54510 Released 2026-08-13 · Red Hat rating Important
    bind security update
    • Red Hat Enterprise Linux AppStream (v. 9) bind-32:9.16.23-40.el9_8.8, bind-chroot-32:9.16.23-40.el9_8.8, bind-dnssec-doc-32:9.16.23-40.el9_8.8 +5
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) bind-devel-32:9.16.23-40.el9_8.8, bind-doc-32:9.16.23-40.el9_8.8, bind-libs-32:9.16.23-40.el9_8.8
  • RHSA-2026:54509 Released 2026-08-13 · Red Hat rating Important
    bind9.16 security update
    • Red Hat Enterprise Linux AppStream (v. 8) bind9.16-32:9.16.23-0.22.el8_10.12, bind9.16-chroot-32:9.16.23-0.22.el8_10.12, bind9.16-dnssec-utils-32:9.16.23-0.22.el8_10.12 +4
    • Red Hat Enterprise Linux CRB (v. 8) bind9.16-devel-32:9.16.23-0.22.el8_10.12, bind9.16-doc-32:9.16.23-0.22.el8_10.12, bind9.16-libs-32:9.16.23-0.22.el8_10.12
  • RHSA-2026:54071 Released 2026-08-12 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images bind-32:9.20.26-0.1.hum1@aarch64, bind-32:9.20.26-0.1.hum1@src, bind-32:9.20.26-0.1.hum1@x86_64 +12

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift Container Platform 4AffectedNo fix yet
Red Hat OpenShift Container Platform 5AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:55441, RHSA-2026:94278
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:55437
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:54509, RHSA-2026:54654
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:54510, RHSA-2026:55442
Red Hat Enterprise Linux AppStream AUS (v.8.4)Fixed RHSA-2026:95477
Red Hat Enterprise Linux AppStream AUS (v.8.6)Fixed RHSA-2026:80501, RHSA-2026:95435
Red Hat Enterprise Linux AppStream E4S (v.8.8)Fixed RHSA-2026:79160, RHSA-2026:95478
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:95242
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:57189
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:94115
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:55441, RHSA-2026:94278
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)Fixed RHSA-2026:95477
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)Fixed RHSA-2026:80501, RHSA-2026:95435
Red Hat Enterprise Linux AppStream TUS (v.8.8)Fixed RHSA-2026:79160, RHSA-2026:95478
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:54654
Red Hat Enterprise Linux BaseOS AUS (v.8.4)Fixed RHSA-2026:95477
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2026:95435
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2026:95478
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)Fixed RHSA-2026:95477
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)Fixed RHSA-2026:95435
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2026:95478
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:54509
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:55437
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:54510, RHSA-2026:55442
Red Hat Enterprise Linux Server (v. 7 ELS)Fixed RHSA-2026:60383
Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)Fixed RHSA-2026:95727
Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)Fixed RHSA-2026:95727
Red Hat Hardened ImagesFixed RHSA-2026:54071
Red Hat OpenShift Container Platform 4.22Fixed RHSA-2026:57362, RHSA-2026:66357
Not affected: 22 products
  • Red Hat CodeReady Linux Builder EUS (v.9.6)
  • Red Hat Enterprise Linux 9
  • Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • Red Hat Enterprise Linux AppStream AUS (v.8.6)
  • Red Hat Enterprise Linux AppStream E4S (v.8.8)
  • Red Hat Enterprise Linux AppStream E4S (v.9.2)
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0)
  • Red Hat Enterprise Linux AppStream EUS (v.9.6)
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6)
  • Red Hat Enterprise Linux AppStream TUS (v.8.8)
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4)
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6)
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8)
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8)
  • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)
  • Red Hat Enterprise Linux Server (v. 7 ELS)
  • Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION)
  • Red Hat Enterprise Linux Server Optional (v. 7 ELS)
  • Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-11721
  2. 2026-10-03 Alias added: GHSA-cq66-h8mj-77hh
  3. 2026-10-09 Fix available: RHSA-2026:79160 · Red Hat
  4. 2026-10-09 Fix available: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · Red Hat
  5. 2026-10-12 Fix available: RHSA-2026:80501 · Red Hat
  6. 2026-10-12 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · Red Hat
  7. 2026-10-30 Affected versions changed · Red Hat
  8. 2026-11-03 Fix available: RHSA-2026:94115 · Red Hat
  9. 2026-11-03 Fix available: RHSA-2026:94278 · Red Hat
  10. 2026-11-03 Fix available: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · Red Hat
  11. 2026-11-04 Fix available: RHSA-2026:95242 · Red Hat
  12. 2026-11-04 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2) · Red Hat
  13. 2026-11-05 Fix available: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4), Red Hat Enterprise Linux BaseOS AUS (v.8.4) +5 · Red Hat
  14. 2026-11-06 Fix available: RHSA-2026:95477 · Red Hat
  15. 2026-11-06 Fix available: RHSA-2026:95435 · Red Hat
  16. 2026-11-06 Fix available: RHSA-2026:95478 · Red Hat
  17. 2026-11-06 Fix available: Red Hat Enterprise Linux Server -EXTENSION(v. 6 ELS-EXTENSION), Red Hat Enterprise Linux Server Optional -EXTENSION (v. 6 ELS -EXTENSION) · Red Hat
  18. 2026-11-06 Fix available: RHSA-2026:95727 · Red Hat

References

Patch 2

Advisory 1

  • TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
  • TI-2023-27571 Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related… CVSS 3.1HIGH 7.5
  • TI-2021-07476 A second vulnerability in BIND's GSSAPI security policy negotiation can be targeted by a buffer overflow attack CVSS 3.1CRITICAL 9.8
  • TI-2023-27773 The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance… CVSS 3.1HIGH 7.5
  • TI-2020-06910 A logic error in code which checks TSIG validity can be used to trigger an assertion failure in tsig.c CVSS 3.1HIGH 7.5
  • TI-2016-02320 buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x… CVSS 3.0HIGH 7.5
See all 192 →

Sources

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