CVE-2026-81563CWE-401

CVE-2026-81563

High · published September 16, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
46.4
In the wild
Unconfirmed
What it is

A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups.

This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00569 · 46.4th percentile
Weakness
CWE-401 · Missing Release of Memory after Effective Lifetime
Published
2026-09-16T18:17Z
References (3)
https://downloads.isc.org/isc/bind9/9.20.29 · [email protected]https://downloads.isc.org/isc/bind9/9.21.26 · [email protected]https://kb.isc.org/docs/cve-2026-81563 · [email protected]
EPSS history
Timeline
  • 18 SEP 04:01Z
    EPSS moved — → 0%
    epss
  • 16 SEP 14:00Z
    SVCB AliasMode additional-data error leaks qpcache references
    cvelistv5