Riskcovery

CVE-2026-1519

Excessive NSEC3 iterations cause high CPU load during insecure delegation validation

State
Published
Severity
7.5 High
Published
Mar 25, 2026
Updated
Sep 17, 2026
Reserved
Jan 28, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hisc
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hredhat-SADP

Weaknesses

  • CWE-606 Unchecked Input for Loop Condition
  • CWE-770 Allocation of Resources Without Limits or Throttling

Affected Products

ProductVersions
BIND 9ISC
  • 9.11.0 through 9.16.50Affected
  • 9.18.0 through 9.18.46Affected
  • 9.20.0 through 9.20.20Affected
  • 9.21.0 through 9.21.19Affected
  • 9.11.3-S1 through 9.16.50-S1Affected
  • 9.18.11-S1 through 9.18.46-S1Affected
  • 9.20.9-S1 through 9.20.20-S1Affected

References

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