ISC BIND 9 up to 9.20.24-S1 DNSSEC Validator assertion

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k1.99+

Summaryinfo

A vulnerability identified as critical has been detected in ISC BIND 9 up to 9.18.50/9.20.24/9.21.23/9.18.50-S1/9.20.24-S1. This vulnerability affects unknown code of the component DNSSEC Validator. This manipulation causes assertion. This vulnerability appears as CVE-2026-13204. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in ISC BIND 9 up to 9.18.50/9.20.24/9.21.23/9.18.50-S1/9.20.24-S1. It has been declared as critical. Affected by this vulnerability is some unknown functionality of the component DNSSEC Validator. The manipulation with an unknown input leads to a assertion vulnerability. The CWE definition for the vulnerability is CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. As an impact it is known to affect availability. The summary by CVE is:

If a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there exist an RRSIG for only one of these types, then BIND may exit unexpectedly with an assertion while validating this proof. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

It is possible to read the advisory at kb.isc.org. This vulnerability is known as CVE-2026-13204 since 06/24/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/22/2026).

Upgrading to version 9.18.50, 9.18.50-S1, 9.20.24, 9.20.24-S1 or 9.21.23 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Assertion
CWE: CWE-617
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: BIND 9 9.18.50/9.18.50-S1/9.20.24/9.20.24-S1/9.21.23

Timelineinfo

06/24/2026 CVE reserved
07/22/2026 +28 days Advisory disclosed
07/22/2026 +0 days VulDB entry created
07/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: isc.org

Advisory: kb.isc.org
Status: Confirmed

CVE: CVE-2026-13204 (🔒)
GCVE (CVE): GCVE-0-2026-13204
GCVE (VulDB): GCVE-100-382363

Entryinfo

Created: 07/22/2026 17:07
Changes: 07/22/2026 17:07 (54)
Complete: 🔍
Cache ID: 216::103

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