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CVE-2026-1519

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
ISC / BIND 9affected 9.11.0 through 9.16.50; affected 9.18.0 through 9.18.46; affected 9.20.0 through 9.20.20; affected 9.21.0 through 9.21.19; affected 9.11.3-S1 through 9.16.50-S1; affected 9.18.11-S1 through 9.18.46-S1; affected 9.20.9-S1 through 9.20.20-S1

CWE

CWE-606

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

CVE

No English description supplied.

redhat-SADP

A flaw was found in BIND. A remote attacker could exploit this vulnerability by sending a maliciously crafted DNSSEC-validated zone to a BIND resolver. This could cause the resolver to consume excessive CPU resources, leading to a denial of service (DoS) for legitimate users.