CVE-2026-1519

HIGH

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

Title source: cna
STIX 2.1

Description

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.

References (28)

Core 28
Core References
Vendor Advisory vendor-advisory
CVE-2026-1519
https://kb.isc.org/docs/cve-2026-1519

Scores

CVSS v3 7.5
EPSS 0.0155
EPSS Percentile 72.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-606 CWE-770
Status published
Products (8)
isc/bind 9.11.0 - 9.16.50
ISC/BIND 9 9.11.0 - 9.16.50
ISC/BIND 9 9.11.3-S1 - 9.16.50-S1
ISC/BIND 9 9.18.0 - 9.18.46
ISC/BIND 9 9.18.11-S1 - 9.18.46-S1
ISC/BIND 9 9.20.0 - 9.20.20
ISC/BIND 9 9.20.9-S1 - 9.20.20-S1
ISC/BIND 9 9.21.0 - 9.21.19
Published Mar 25, 2026
Tracked Since Mar 25, 2026