CVE-2026-76163
Description
A flaw was found in BIND. A remote attacker can exploit this vulnerability by sending a specially crafted TKEY query to a BIND server configured without a global 'options' block in its 'named.conf' file. This can lead to an assertion failure, causing the BIND program to unexpectedly terminate. This results in a Denial of Service (DoS), making the affected server unavailable.
Statement
This is an Important denial of service flaw in BIND. If the named.conf file lacks a global options block, a remote attacker can send a crafted TKEY query, leading to an assertion failure and unexpected program termination. This issue impacts the availability of the DNS service.
Mitigation
To mitigate this issue, ensure that the BIND configuration file (`named.conf`) includes a global `options` block. If no such block exists, adding an empty `options {}` block will prevent the vulnerability. After modifying `named.conf`, the `named` service must be restarted for the changes to take effect. This may temporarily interrupt DNS resolution.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker that can trigger an assert statement can still lead to a denial of service if the relevant code can be triggered by an attacker, and if the scope of the assert() extends beyond the attacker's own session.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
