Cache Injection via Lenient Record Acceptance in BIND 9 (up to 9.21.12)
CVE-2025-40778 Published on October 22, 2025
Cache poisoning attacks with unsolicited RRs
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.
Vulnerability Analysis
CVE-2025-40778 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. An automatable proof of concept (POC) exploit exists. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.
Weakness Type
Acceptance of Extraneous Untrusted Data With Trusted Data
The software, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted.
Products Associated with CVE-2025-40778
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Affected Versions
ISC BIND 9:- Version 9.11.0, <= 9.16.50 is affected.
- Version 9.18.0, <= 9.18.39 is affected.
- Version 9.20.0, <= 9.20.13 is affected.
- Version 9.21.0, <= 9.21.12 is affected.
- Version 9.11.3-S1, <= 9.16.50-S1 is affected.
- Version 9.18.11-S1, <= 9.18.39-S1 is affected.
- Version 9.20.9-S1, <= 9.20.13-S1 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.