Description
Clients using DNS-over-HTTPS (DoH) can exhaust a DNS resolver's CPU and/or memory by flooding it with crafted valid or invalid HTTP/2 traffic.
This issue affects BIND 9 versions 9.18.0 through 9.18.32, 9.20.0 through 9.20.4, 9.21.0 through 9.21.3, and 9.18.11-S1 through 9.18.32-S1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ISC | BIND 9 | 9.18.0 – ≤ 9.18.32, 9.20.0 – ≤ 9.20.4, 9.21.0 – ≤ 9.21.3, 9.18.11-S1 – ≤ 9.18.32-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 | 1:9.20.5-1 | — |
| Debian 13 | bind9 | 1:9.20.5-1 | — |
| Debian 12 | bind9 | 1:9.18.33-1~deb12u2 | DSA-5854-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | isc-dhcp | No fix yet | — |
| Ubuntu 25.10 | isc-dhcp | No fix yet | — |
| Ubuntu 24.04 LTS | bind9 | 1:9.18.30-0ubuntu0.24.04.2 | USN-7241-1 |
| Ubuntu 24.04 LTS | isc-dhcp | No fix yet | — |
| Ubuntu 22.04 LTS | bind9 | 1:9.18.30-0ubuntu0.22.04.2 | USN-7241-1 |
| Ubuntu 22.04 LTS | bind9-libs | No fix yet | — |
| Ubuntu 20.04 LTS | bind9 | 1:9.18.30-0ubuntu0.20.04.2 | USN-7241-1 |
| Ubuntu 20.04 LTS | bind9-libs | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | isc-dhcp | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | bind9.18 +6 | 32:9.18.29-1.el9_5.1 | RHSA-2025:1670 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | bind9.18 +6 | 32:9.18.29-1.el9_5.1 | ALSA-2025:1670 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 9 | bind9.18 | 2:9.18.29-1.el9_5.1 | RLSA-2025:1670 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | bind | 9.20.9-150700.3.3.1 | SUSE-SU-2025:01787-1 |
| SLES 15 SP6 | bind | 9.18.33-150600.3.6.1 | SUSE-SU-2025:0355-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | bind | 9.20.5-1.1 | openSUSE-SU-2025:14719-1 |
| openSUSE Leap 15.6 | bind | 9.18.33-150600.3.6.1 | SUSE-SU-2025:0355-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | bind | 9.18.33-r0 | — |
| Alpine v3.23 | bind | 9.18.33-r0 | — |
| Alpine v3.22 | bind | 9.18.33-r0 | — |
| Alpine v3.21 | bind | 9.18.33-r0 | — |
| Alpine v3.20 | bind | 9.18.33-r0 | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | bind | 9.18.33-r0 | — |
| Alpine v3.18 | bind | 9.18.33-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | bind +7 | 32:9.18.33-1.amzn2023.0.2 | ALAS2023-2025-838 |
| Amazon Linux 2 | bind +15 | 32:9.11.4-26.P2.amzn2.13.11 | ALAS2-2025-2751 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | bind | 9.20.5-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | bind9.18 +6 | 32:9.18.29-1.el9_5.1 | ELSA-2025-1670 |
Advisories 13
- ALSA-2025:1670 Important: bind9.18 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:1670 Red Hat Security Advisory: bind9.18 security update Red Hat Security Advisories (RHSA) · Oct 14, 2026
- WID-SEC-2025-0217 Internet Systems Consortium BIND: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · May 17, 2026
- USN-7241-1 bind9 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5854-1 bind9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RLSA-2025:1670 Important: bind9.18 security update Rocky Linux Security Advisories · Feb 4, 2026
- SUSE-SU-2025:0355-1 Security update for bind SUSE / openSUSE Security Updates · Feb 4, 2026
- VDE-2025-053 Phoenix Contact: Multiple Vulnerabilities in PLCnext Firmware CERT@VDE · Jul 8, 2025
- SUSE-SU-2025:01787-1 Security update for bind SUSE / openSUSE Security Updates · May 31, 2025
- openSUSE-SU-2025:14719-1 bind-9.20.5-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- ELSA-2025-1670 Important: bind9.18 security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Feb 21, 2025
- ALAS2023-2025-838 Important: bind security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 5, 2025
- ALAS2-2025-2751 Important: bind security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Feb 4, 2025
References
- CVE-2024-12705 vendor-advisory