Vulnerability · Published Mar 25, 2026 · Assigned by isc
CVE-2026-3104Memory leak in code preparing DNSSEC proofs of non-existence
High 7.5
In plain English
A high-severity security flaw in BIND 9 from ISC. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 46.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A specially crafted domain can be used to cause a memory leak in a BIND resolver simply by querying this domain. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.22 | bind | 9.20.21-r0 | ALPINE-CVE-2026-3104 |
| Alpine:v3.23 | bind | 9.20.21-r0 | ALPINE-CVE-2026-3104 |
| Alpine:v3.24 | bind | 9.20.21-r0 | ALPINE-CVE-2026-3104 |
| Debian:13 | bind9 | 1:9.20.21-1~deb13u1 | DEBIAN-CVE-2026-3104 |
| Debian:14 | bind9 | 1:9.20.21-1 | DEBIAN-CVE-2026-3104 |
| Ubuntu:25.10 | bind9 | 1:9.20.11-1ubuntu2.2 | UBUNTU-CVE-2026-3104 |
| Ubuntu:22.04:LTS | bind9-libs | no fix listed | UBUNTU-CVE-2026-3104 |
| Ubuntu:24.04:LTS | isc-dhcp | no fix listed | UBUNTU-CVE-2026-3104 |
| Ubuntu:25.10 | isc-dhcp | no fix listed | UBUNTU-CVE-2026-3104 |
| Ubuntu:26.04:LTS | isc-dhcp | no fix listed | UBUNTU-CVE-2026-3104 |
Affected products (as reported)
Weakness: CWE-772 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- CVE-2026-3104 vendor-advisory
- https://downloads.isc.org/isc/bind9/9.20.21 patch
- https://downloads.isc.org/isc/bind9/9.21.20 patch
- https://access.redhat.com/security/cve/CVE-2026-3104 vdb-entry, x_refsource_REDHAT
- RHBZ#2451310 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3104.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:6935 vendor-advisory, x_refsource_REDHAT