CVE-2025-40778Public exploitNetwork attack vectorHinoki check available

Cache poisoning via unsolicited DNS records

Published Oct 22, 2025 · Updated Oct 22, 2025

Cache poisoning in affected Internet Systems Consortium BIND 9 resolvers allows remote attackers to inject forged DNS records. During answer processing, named accepts records unrelated to the outstanding query and caches them instead of rejecting unsolicited data. The attack requires a recursive resolver, an unsigned zone or disabled DNSSEC validation, and a successful spoofing race; poisoned entries alter later name resolution.

CVSS severity8.6
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Cache poisoning in affected Internet Systems Consortium BIND 9 resolvers allows remote attackers to inject forged DNS records. During answer processing, named accepts records unrelated to the outstanding query and caches them instead of rejecting unsolicited data. The attack requires a recursive resolver, an unsigned zone or disabled DNSSEC validation, and a successful spoofing race; poisoned entries alter later name resolution.

The record

CVE
CVE-2025-40778
Published
Oct 22, 2025
Updated
Oct 22, 2025
Vendor
Internet Systems Consortium
Product
BIND 9
Classifications
CWE-349, T1565.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=9.11.0 <=9.16.50
  2. Affected versionversion=9.11.3-S1 <=9.16.50-S1
  3. Affected versionversion=9.18.0 <=9.18.39
  4. Affected versionversion=9.18.11-S1 <=9.18.39-S1
  5. Affected versionversion=9.20.0 <=9.20.13
  6. Affected versionversion=9.20.9-S1 <=9.20.13-S1
  7. Affected versionversion=9.21.0 <=9.21.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Internet Systems Consortium · BIND 9version=9.11.0 <=9.16.50; version=9.11.3-S1 <=9.16.50-S1; version=9.18.0 <=9.18.39; version=9.18.11-S1 <=9.18.39-S1; version=9.20.0 <=9.20.13; version=9.20.9-S1 <=9.20.13-S1; version=9.21.0 <=9.21.12

Published CVSS scores

8.6Internet Systems Consortium (ISC)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-349Acceptance of Extraneous Untrusted Data With Trusted Data
T1565.002Transmitted Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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