CVE-2026-3592 PUBLISHED

Amplification vulnerabilities via self-pointed glue records

Assigner: isc
Reserved: 05.03.2026 Published: 20.05.2026 Updated: 20.05.2026

BIND resolvers are vulnerable to an amplified resource consumption/exhaustion attack. If a victim resolver makes a query to a specially crafted zone, the resolver will consume disproportionate resources. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Product Status

Vendor ISC
Product BIND 9
Versions Default: unaffected
  • affected from 9.11.0 to 9.16.50 (incl.)
  • affected from 9.18.0 to 9.18.48 (incl.)
  • affected from 9.20.0 to 9.20.22 (incl.)
  • affected from 9.21.0 to 9.21.21 (incl.)
  • affected from 9.11.3-S1 to 9.16.50-S1 (incl.)
  • affected from 9.18.11-S1 to 9.18.48-S1 (incl.)
  • affected from 9.20.9-S1 to 9.20.22-S1 (incl.)

Exploits

We are not aware of any active exploits.

Workarounds

No workarounds known.

Solutions

Upgrade to the patched release most closely related to your current version of BIND 9: 9.18.49, 9.20.23, 9.21.22, 9.18.49-S1, or 9.20.23-S1.

Credits

  • ISC would like to thank Shuhan Zhang from Tsinghua University for bringing this vulnerability to our attention.

References

Problem Types

  • CWE-408 Incorrect Behavior Order - Early Amplification CWE

Impacts

  • An attacker may be able to cause the resolver to consume disproportionate amounts of bandwidth in the attempt to resolve the name. Impairment of TCP may also be seen. The issue predominately affects recursive resolvers. Authoritative-only servers containing only trustworthy zones and names should be unaffected. If an authoritative server can be induced to look up an attack domain (e.g., if loading a zone from an untrusted source), it may be possible to trigger the issue.