Resource Exhaustion Vulnerability in BIND by ISC

CVE-2026-19630

What is CVE-2026-19630?

CVE-2026-19630 is a resource exhaustion vulnerability found in BIND (Berkeley Internet Name Domain), a widely used Domain Name System (DNS) software produced by ISC (Internet Systems Consortium). The vulnerability arises due to the handling of inbound DNS protocol messages that conform to a specific structure, which does not impose restrictions on processing. This allows an attacker to craft DNS messages containing a maliciously large number of such structures, leading to excessive consumption of CPU resources and memory. The BIND versions affected include 9.11.0 through 9.18.50, 9.20.0 through 9.20.29, and 9.21.0 through 9.21.26, as well as specific S1 versions. If exploited, this vulnerability could significantly degrade the performance of a BIND resolver, causing service interruptions and potential downtime for organizations relying on DNS services for their operations.

Potential impact of CVE-2026-19630

1. Service Disruption: The exploitation of this vulnerability can lead to severe degradation in the performance of DNS services, resulting in outages and unavailability of critical online services for organizations and their users.

2. Resource Drain: By consuming disproportionate amounts of CPU and memory, an attacker can hinder the capabilities of systems utilizing BIND, affecting not only the DNS resolution process but also the overall efficiency of network operations.

3. Increased Attack Surface: As organizations experience service disruptions, they may become more vulnerable to further attacks, including denial-of-service attempts or exploitation of additional vulnerabilities, escalating the risk profile of their network infrastructure.

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