VDB-364881 · CVE-2026-5946 · Nessus 315661

ISC BIND up to 9.21.21 named recursion

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.3	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic has been found in ISC BIND up to 9.21.21. Affected by this vulnerability is an unknown functionality of the component named. Performing a manipulation results in recursion. This vulnerability is identified as CVE-2026-5946. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in ISC BIND up to 9.21.21. This affects some unknown processing of the component named. The manipulation with an unknown input leads to a recursion vulnerability. CWE is classifying the issue as CWE-674. The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack. This is going to have an impact on availability. The summary by CVE is:

Multiple flaws have been identified in `named` related to the handling of DNS messages whose CLASS is not Internet (`IN`) — for example, `CHAOS` or `HESIOD`, or DNS messages that specify meta-classes (`ANY` or `NONE`) in the question section. Specially crafted requests reaching the affected code paths — recursion, dynamic updates (`UPDATE`), zone change notifications (`NOTIFY`), or processing of `IN`-specific record types in non-`IN` data — can cause assertion failures in `named`. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

The advisory is shared at kb.isc.org. This vulnerability is uniquely identified as CVE-2026-5946 since 04/09/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 315661 (ISC BIND 9.11.0 < 9.18.49 / 9.11.3-S1 < 9.18.49-S1 / 9.18.0 < 9.18.49 / 9.18.11-S1 < 9.18.49-S1 / 9.20.0 < 9.20.23 / 9.20.9-S1 < 9.20.23-S1 / 9.21.0 < 9.21.22 Assertion Failure (cve-2026-5946)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (315661) and CERT Bund (WID-SEC-2026-1626). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

Debian Linux
Red Hat Enterprise Linux
Fedora Linux
Ubuntu Linux
Oracle Linux
Infoblox NIOS
SUSE openSUSE
Internet Systems Consortium BIND

Productinfo

Type

Domain Name Software

Vendor

Name

BIND

Version

License

open-source

Website

Vendor: https://www.isc.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (isc): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Recursion
CWE: CWE-674 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 315661
Nessus Name: ISC BIND 9.11.0 < 9.18.49 / 9.11.3-S1 < 9.18.49-S1 / 9.18.0 < 9.18.49 / 9.18.11-S1 < 9.18.49-S1 / 9.20.0 < 9.20.23 / 9.20.9-S1 < 9.20.23-S1 / 9.21.0 < 9.21.22 Assertion Failure (cve-2026-5946)