CVE-2026-1519

Summary

If a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU. Authoritative-only servers are generally unaffected, although there are circumstances where authoritative servers may make recursive queries (see: https://kb.isc.org/docs/why-does-my-authoritative-server-make-recursive-queries). This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.46, 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.46-S1, and 9.20.9-S1 through 9.20.20-S1.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://downloads.isc.org/isc/bind9/9.18.47 ↗

Additional information

• NVD record
• https://downloads.isc.org/isc/bind9/9.18.47Patch
• https://downloads.isc.org/isc/bind9/9.20.21Patch
• https://downloads.isc.org/isc/bind9/9.21.20Patch
• https://kb.isc.org/docs/cve-2026-1519Advisory
• https://lists.debian.org/debian-lts-announce/2026/04/msg00008.htmlAdvisory
• https://access.redhat.com/errata/RHSA-2026:11371
• https://access.redhat.com/errata/RHSA-2026:11372
• https://access.redhat.com/errata/RHSA-2026:15890