Description
For a secondary zone with transfers restricted by TSIG, `named` may start to serve the data provided in a zone transfer before the final message with the TSIG signature arrives. This could allow an attacker that does not actually possess a valid TSIG signature to send unauthorized zone contents to a secondary server. Although no TSIG signature ever arrives, `named` does not rollback to the pre-transfer state. To exploit the vulnerability, the transfer must be a multi-message TCP IXFR, as described by RFC 8945.
This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ISC | BIND 9 | 9.11.0 – ≤ 9.18.50, 9.20.0 – ≤ 9.20.27, 9.21.0 – ≤ 9.21.25, 9.11.3-S1 – ≤ 9.18.50-S1, 9.20.9-S1 – ≤ 9.20.27-S1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | bind9 | 1:9.20.29-1 | — |
| Debian 13 | bind9 | 1:9.20.29-1~deb13u1 | — |
| Debian 12 | bind9 | 1:9.18.49-1~deb12u3 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | bind9 | 1:9.20.24-1ubuntu3.1 | USN-8969-1 |
| Ubuntu 26.04 LTS | bind9 | 1:9.20.24-1ubuntu0.4 | USN-8969-1, USN-8929-1 |
| Ubuntu 26.04 LTS | isc-dhcp | No fix yet | — |
| Ubuntu 24.04 LTS | bind9 | 1:9.18.39-0ubuntu0.24.04.8 | USN-8969-1, USN-8929-1 |
| Ubuntu 24.04 LTS | isc-dhcp | No fix yet | — |
| Ubuntu 22.04 LTS | bind9 | 1:9.18.39-0ubuntu0.22.04.7 | USN-8969-1, USN-8929-1 |
| Ubuntu 22.04 LTS | bind9-libs | No fix yet | — |
| Ubuntu 20.04 LTS | bind9-libs | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | isc-dhcp | No fix yet | — |
| Ubuntu Pro 20.04 LTS | bind9 | 1:9.18.30-0ubuntu0.20.04.2+esm3 | USN-8929-1 |
| Ubuntu Pro 18.04 LTS | bind9 | 1:9.11.3+dfsg-1ubuntu1.19+esm6 | USN-8929-1 |
| Ubuntu Pro 16.04 LTS | bind9 | 1:9.10.3.dfsg.P4-8ubuntu1.19+esm11 | USN-8929-1 |
| Ubuntu Pro 14.04 LTS | bind9 | 1:9.9.5.dfsg-3ubuntu0.19+esm15 | USN-8929-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | bind +6 | 9.20.29-0.1.hum1 | RHSA-2026:68279 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | bind | 9.20.29-150700.3.32.2 | SUSE-SU-2026:4285-1 |
| SLES 15 SP6 | bind | 9.18.50-150600.3.35.1 | SUSE-SU-2026:4608-1 |
| SLES 15 SP5 | bind | 9.16.50-150500.8.46.1 | SUSE-SU-2026:4772-1 |
| SLES 15 SP4 | bind | 9.16.50-150400.5.70.1 | SUSE-SU-2026:4664-1 |
| SLES 12 SP5 | bind | 9.11.22-3.77.1 | SUSE-SU-2026:4635-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | bind | 9.20.29-160000.1.1 | SUSE-SU-2026:24157-1 |
| SLES for SAP 15 SP6 | bind | 9.18.50-150600.3.35.1 | SUSE-SU-2026:4608-1 |
| SLES for SAP 15 SP5 | bind | 9.16.50-150500.8.46.1 | SUSE-SU-2026:4772-1 |
| SLES for SAP 15 SP4 | bind | 9.16.50-150400.5.70.1 | SUSE-SU-2026:4664-1 |
| SLES 16.0 | bind | 9.20.29-160000.1.1 | SUSE-SU-2026:24157-1 |
| SLE Micro 5.5 | bind | 9.16.50-150500.8.46.1 | SUSE-SU-2026:4772-1 |
| SLE HPC 15 SP5 | bind | 9.16.50-150500.8.46.1 | SUSE-SU-2026:4772-1 |
| SLE HPC 15 SP4 | bind | 9.16.50-150400.5.70.1 | SUSE-SU-2026:4664-1 |
| SUSE Multi Linux Manager Tools SLE-Micro-5 | bind | 9.16.6-150000.12.97.1 | SUSE-SU-2026:5118-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | bind | 9.20.29-1.1 | openSUSE-SU-2026:11916-1 |
| openSUSE Leap 16.0 | bind | 9.20.29-160000.1.1 | openSUSE-SU-2026:22049-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | bind | 9.20.29-r0 | — |
| Alpine v3.23 | bind | 9.20.29-r0 | — |
| Alpine v3.22 | bind | 9.20.29-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | bind +7 | 32:9.18.50-1.amzn2023.0.3 | ALAS2023-2026-3137 |
| Amazon Linux 2 | bind +15 | 32:9.11.4-26.P2.amzn2.13.18 | ALAS2-2026-3995 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | bind | 9.20.30-1 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | bind +2 | 9.20.30-r0 | — |
| Wolfi rolling | bind-libs +3 | 9.20.29-r1 | — |
Advisories 15
- WID-SEC-2026-3420 Internet Systems Consortium BIND: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:5118-1 Security update for bind SUSE / openSUSE Security Updates · Nov 5, 2026
- USN-8969-1 bind9 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- SUSE-SU-2026:4772-1 Security update for bind SUSE / openSUSE Security Updates · Oct 21, 2026
- openSUSE-SU-2026:22049-1 Security update for bind SUSE / openSUSE Security Updates · Oct 19, 2026
- USN-8929-1 bind9 vulnerabilities Ubuntu Security Notices (USN) · Oct 17, 2026
- RHSA-2026:68279 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- SUSE-SU-2026:24157-1 Security update for bind SUSE / openSUSE Security Updates · Oct 16, 2026
- SUSE-SU-2026:4664-1 Security update for bind SUSE / openSUSE Security Updates · Oct 15, 2026
- SUSE-SU-2026:4635-1 Security update for bind SUSE / openSUSE Security Updates · Oct 13, 2026
- ALAS2-2026-3995 Important: bind security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- SUSE-SU-2026:4608-1 Security update for bind SUSE / openSUSE Security Updates · Oct 10, 2026
- openSUSE-SU-2026:11916-1 bind-9.20.29-1.1 on GA media SUSE / openSUSE Security Updates · Sep 30, 2026
- ALAS2023-2026-3137 Important: bind security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026
- SUSE-SU-2026:4285-1 Security update for bind SUSE / openSUSE Security Updates · Sep 23, 2026
References
- CVE-2026-19033 vendor-advisory
- https://downloads.isc.org/isc/bind9/9.20.29 patch
- https://downloads.isc.org/isc/bind9/9.21.26 patch