Vulnerability in Isc Bind 9

CVE-2025-40776

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.002 (12.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-40776: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Isc Bind 9 — versions 9.11.3-S1, 9.18.11-S1, 9.20.9-S1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-40776?
CVE-2025-40776 is a high-severity vulnerability in Isc Bind 9, classified under CWE-349. CVSS score: 8.6/10. Published 2025-07-16.
How severe is CVE-2025-40776?
High severity. CVSS v3 base score is 8.6 out of 10.