Birthday Attack against Resolvers supporting ECS
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.2%
exploitation probability
0.2%top 90% of all CVEs
observed exploitation
nono source reports it
A `named` caching resolver that is configured to send ECS (EDNS Client Subnet) options may be vulnerable to a cache-poisoning attack.
This issue affects BIND 9 versions 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.37-S1, and 9.20.9-S1 through 9.20.10-S1.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
Affected products
ISC · BIND 9References
https://kb.isc.org/docs/cve-2025-40776