ISC BIND 9 up to 9.21.23 RPZ Processing input validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.5$5k-$25k2.67

Summaryinfo

A vulnerability, which was classified as critical, was found in ISC BIND 9 up to 9.18.50/9.18.50-S1/9.20.24/9.20.24-S1/9.21.23. The impacted element is an unknown function of the component RPZ Processing. The manipulation results in input validation. This vulnerability is identified as CVE-2026-11331. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as critical has been found in ISC BIND 9 up to 9.18.50/9.18.50-S1/9.20.24/9.20.24-S1/9.21.23. Affected is some unknown functionality of the component RPZ Processing. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on integrity, and availability. CVE summarizes:

An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It also may lead to an unexpected exit of the BIND 9 software. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

The advisory is shared for download at kb.isc.org. This vulnerability is traded as CVE-2026-11331 since 06/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/22/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.5

VulDB Base Score: 6.5
VulDB Temp Score: 6.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Input validation
CWE: CWE-20
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: 🔒

Timelineinfo

06/05/2026 CVE reserved
07/22/2026 +47 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-2026-11331 (🔒)
GCVE (CVE): GCVE-0-2026-11331
GCVE (VulDB): GCVE-100-382356

Entryinfo

Created: 07/22/2026 17:00
Changes: 07/22/2026 17:00 (53)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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