REDHAT-BUG-2451310: High severity ISC BIND 9 vulnerability

Published Mar 25, 2026
·
Updated

A specially crafted domain can be used to cause a memory leak in a BIND resolver simply by querying this domain. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.

Affected Software

1 affected component
ISC BIND 9>=9.20.0<=9.20.20, >=9.21.0<=9.21.19, >=9.20.9-S1<=9.20.20-S1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.20.20
  2. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.21.19
  3. Upgrade

    Upgrade BIND 9 to a version that resolves this vulnerability.

    Fixed in 9.20.20-S1

Event History

Mar 25, 2026
Data Sourced
via Red Hat·02:02 PM
DescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of REDHAT-BUG-2451310?

The severity of REDHAT-BUG-2451310 is classified as high with a score of 7.

2

How do I fix REDHAT-BUG-2451310?

To fix REDHAT-BUG-2451310, update to the latest versions of BIND 9 that have addressed this vulnerability.

3

What is the impact of REDHAT-BUG-2451310 on BIND resolvers?

REDHAT-BUG-2451310 can cause a memory leak in BIND resolvers simply by querying a specially crafted domain.

4

Which versions of BIND 9 are affected by REDHAT-BUG-2451310?

The affected versions of BIND 9 include 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1.

5

What should I do if I am using an affected version of BIND 9?

If you are using an affected version of BIND 9, you should upgrade to a patched version as soon as possible to mitigate the risk.

Contact

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