CPU Exhaustion via Malformed DNSKEY in BIND 9 (9.189.21)
CVE-2025-8677 Published on October 22, 2025
Resource exhaustion via malformed DNSKEY handling
Querying for records within a specially crafted zone containing certain malformed DNSKEY records can lead to CPU exhaustion.
This issue affects BIND 9 versions 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
Vulnerability Analysis
CVE-2025-8677 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is an Amplification Vulnerability?
Software that does not appropriately monitor or control resource consumption can lead to adverse system performance. This situation is amplified if the software allows malicious users or attackers to consume more resources than their access level permits. Exploiting such a weakness can lead to asymmetric resource consumption, aiding in amplification attacks against the system or the network.
CVE-2025-8677 has been classified to as an Amplification vulnerability or weakness.
Products Associated with CVE-2025-8677
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Affected Versions
ISC BIND 9:- 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 9.18.11-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.