CVE-2026-97313
Description
A flaw was found in BIND. A remote attacker can cause a denial of service (DoS) by sending a sequence of recursive and non-recursive queries to an affected server. When BIND is configured to handle recursive queries alongside multiple Response Policy Zones (RPZ) with differing recursion settings, processing these queries triggers an assertion failure. This failure causes the service to crash and terminate abruptly.
Statement
Red Hat rates this vulnerability as Important because an unauthenticated remote attacker can crash the BIND name service, causing a denial of service for all dependent infrastructure. Exploitation requires a specific, non-default deployment where recursive queries are permitted alongside multiple response policy zones configured with conflicting recursive-only options. Default Red Hat Enterprise Linux configurations do not define response policy zones and are therefore not exposed unless administrators have explicitly implemented this combination of policies.
Mitigation
Ensure all Response Policy Zones (RPZ) configured in `/etc/named.conf` use identical `recursive-only` settings. For example, ensure all RPZ definitions consistently specify `recursive-only yes;` or `recursive-only no;`, eliminating conflicting policies.
Alternatively, limit recursive query privileges strictly to authorized clients by configuring the `allow-recursion` option with an access control list (ACL).
After modifying the configuration, validate the syntax and reload the service:
named-checkconf
systemctl reload named
Caveats:
Aligning the `recursive-only` setting across RPZ zones may alter policy enforcement behavior for non-recursive queries. Restricting recursion prevents unauthorized networks from performing recursive lookups.
Warning:
Reloading or restarting the `named` service may cause a momentary pause in active DNS query processing.
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
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