CVE-2026-81736
published 2026-09-16CVE-2026-81736: If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate…
PriorityP344high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.57%
46.8th percentile
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| isc | bind | — | — |
| isc | bind_9 | 9.18.0 – 9.18.50 | — |
| isc | bind_9 | 9.18.11-S1 – 9.18.50-S1 | — |
| isc | bind_9 | 9.20.0 – 9.20.27 | — |
| isc | bind_9 | 9.20.9-S1 – 9.20.27-S1 | — |
| isc | bind_9 | 9.21.0 – 9.21.25 | — |
| ubuntu | bind9 | — | — |
CVSS provenance
nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vendor_ubuntu8.6HIGH
vendor_redhat7.5HIGH
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VulDB
ISC BIND up to 9.21.25 Resolver resource consumption (Nessus ID 347971)
vuldb·2026-09-18·CVSS 7.5
CVE-2026-81736 [HIGH] ISC BIND up to 9.21.25 Resolver resource consumption (Nessus ID 347971)
A vulnerability identified as problematic has been detected in ISC BIND up to 9.18.50/9.18.50-S1/9.20.27/9.20.27-S1/9.21.25. The affected element is an unknown function of the component Resolver. Performing a manipulation results in resource consumption.
This vulnerability is cataloged as CVE-2026-81736. It is possible to initiate the attack remotely. There is no exploit available.
GHSA
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
ghsa_unreviewed·2026-09-16
CVE-2026-81736 [HIGH] CWE-1050 If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Ubuntu
Bind vulnerabilities
vendor_ubuntu·2026-10-14·CVSS 8.6
CVE-2026-19033 [HIGH] Bind vulnerabilities
Title: Bind vulnerabilities
Summary: Several security issues were fixed in Bind.
Zuyao Xu and Xiang Li discovered that Bind incorrectly handled certain
malformed DNSKEY records. A remote attacker could possibly use this issue
to cause Bind to consume resources, resulting in a denial of service. This
issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 18.04
LTS. (CVE-2025-8677)
Yuxiao Wu, Yunyi Zhang, Baojun Liu, and Haixin Duan discovered that Bind
incorrectly accepted certain records from answers. A remote attacker could
possibly use this issue to perform a cache poisoning attack. This issue
only affected Ubuntu 18.04 LTS. (CVE-2025-40778)
Samy Medjahed discovered that Bind incorrectly handled insecure delegation
validation. A remote attacker could possibly use this iss
Red Hat
bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records
vendor_redhat·2026-09-16·CVSS 7.5
CVE-2026-81736 [HIGH] CWE-606 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records
bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
A flaw was found in BIND 9. A remote attacker can exploit this vulnerability by querying a BIND resolver for the root of a specially crafted, cached tree of SVCB/HTTPS AliasMode records. This action causes the resolver to spend a disproportionate amount of CPU time constructing the response, leading to a denial of service (DoS) condition. This can mak
No detection rules found.
No public exploits indexed.
Hackernews
BIND 9 Update Fixes 14 Flaws, Including an Unauthenticated Crash Over DNS-over-HTTPS
blogs_hackernews·2026-09-17·CVSS 5.9
CVE-2026-19662 [MEDIUM] BIND 9 Update Fixes 14 Flaws, Including an Unauthenticated Crash Over DNS-over-HTTPS
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## BIND 9 Update Fixes 14 Flaws, Including an Unauthenticated Crash Over DNS-over-HTTPS
The Internet Systems Consortium (ISC) has released BIND 9.20.29 and 9.21.26 to fix fourteen security flaws it disclosed on 16 September in BIND 9, its open-source DNS server software. One of them affects any BIND server that answers DNS-over-HTTPS (DoH).
A sender with no credentials can crash the server process, named, with a single request that carries an invalid SIG(0) signature, if the sender closes the connection before named finishes checking the signature.
ISC said in its advisories that it is not aware of any of the fourteen being ex
Bugzilla
CVE-2026-81736 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records [fedora-all]
bugzilla·2026-09-17·CVSS 7.5
CVE-2026-81736 [HIGH] CVE-2026-81736 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records [fedora-all]
CVE-2026-81736 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
Bugzilla
CVE-2026-81736 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records
bugzilla·2026-09-16·CVSS 7.5
CVE-2026-81736 [HIGH] CVE-2026-81736 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records
CVE-2026-81736 bind: BIND 9: Remote Denial of Service via cached SVCB/HTTPS AliasMode records
If a BIND resolver has cached a tree of SVCB/HTTPS AliasMode records, and is then queried for the root of that tree, the resolver will spend disproportionate CPU time constructing the response.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.
2026-09-16
Published