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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-1519

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

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Status
Published
Published
Updated
Assigning organization
isc

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

ISC BIND 9

Default version status: unaffected

  • 9.11.0 to ≤ 9.16.50affected
  • 9.18.0 to ≤ 9.18.46affected
  • 9.20.0 to ≤ 9.20.20affected
  • 9.21.0 to ≤ 9.21.19affected
  • 9.11.3-S1 to ≤ 9.16.50-S1affected
  • 9.18.11-S1 to ≤ 9.18.46-S1affected
  • 9.20.9-S1 to ≤ 9.20.20-S1affected

References