CVE-2025-40778

Publication date 22 October 2025

Last updated 17 October 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

8.6 · High

Score breakdown

Description

Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.

Read the notes from the security team

Status

Package Ubuntu Release Status
bind9 26.10 stonking
Fixed in 1:9.20.11-1ubuntu3
26.04 LTS resolute
Fixed in 1:9.20.11-1ubuntu3
25.10 questing
Fixed in 1:9.20.11-1ubuntu2.1
25.04 plucky
Fixed in 1:9.20.11-0ubuntu0.2
24.04 LTS noble
Fixed in 1:9.18.39-0ubuntu0.24.04.2
22.04 LTS jammy
Fixed in 1:9.18.39-0ubuntu0.22.04.2
20.04 LTS focal
Fixed in 1:9.18.30-0ubuntu0.20.04.2+esm1
18.04 LTS bionic
Fixed in 1:9.11.3+dfsg-1ubuntu1.19+esm6
16.04 LTS xenial Ignored end of ESM support, was needs-triage
14.04 LTS trusty Ignored changes too intrusive
isc-dhcp 26.10 stonking Not in release
26.04 LTS resolute
Needs evaluation
25.10 questing Ignored end of life, was needs-triage
25.04 plucky Ignored end of life, was needs-triage
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
bind9-libs 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
25.04 plucky Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation

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Notes

alexmurray

As of isc-dhcp-4.4.3-1, isc-dhcp vendors bind9 libs

mdeslaur

in focal and jammy, isc-dhcp uses the bind9-libs package per upstream, 9.11+, need to check This is unlikely to affect isc-dhcp's use of bind9-libs and the vendored bind9 libs, marking as negligible

john-breton

The fix narrows what the resolver caches from responses. On trusty and xenial, which lack DNS cookies, the backport changed resolver behaviour (cached authority data, forwarding, stub zones, RPZ NSDNAME triggers), so it is not being fixed there.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
bind9

Severity score breakdown

CVSS version: CVSS v3.0

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

References

Related Ubuntu Security Notices (USN)

Other references

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