CVE-2026-3039: BIND Servers Face High-Severity Memory Exhaustion Vulnerability
The National Vulnerability Database has identified CVE-2026-3039, a critical vulnerability affecting BIND DNS servers configured for TKEY-based authentication using GSS-API tokens. Attackers can exploit this flaw by sending specially crafted packets, leading to excessive memory consumption and potential denial-of-service conditions. This issue is particularly relevant for organizations utilizing BIND within Active Directory integrated DNS or Kerberos-secured DNS environments.
The vulnerability impacts numerous BIND 9 versions, including specific release lines up to 9.16.50, 9.18.48, 9.20.22, and 9.21.21, along with their respective security-patched (S1) variants. With a CVSS score of 7.5 (HIGH), the potential for network-based exploitation without requiring privileges or user interaction makes this a significant concern for network infrastructure security. Defenders must prioritize patching or mitigating these vulnerable BIND instances.
What This Means For You
- If your organization uses BIND for DNS services, especially in an Active Directory or Kerberos environment, check your BIND 9 version against the affected list immediately. Prioritize patching to the latest stable release to prevent potential denial-of-service attacks that could disrupt critical name resolution services.
Related ATT&CK Techniques
🛡️ Detection Rules
5 rules · 6 SIEM formats5 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
Web Application Exploitation Attempt — CVE-2026-3039
title: Web Application Exploitation Attempt — CVE-2026-3039
id: scw-2026-05-20-1
status: experimental
level: high
description: |
Detects common exploitation patterns targeting web applications. Review CVE-2026-3039 advisories for specific indicators.
author: SCW Feed Engine (auto-generated)
date: 2026-05-20
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-3039/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri-query|contains:
- '..'
- 'SELECT'
- 'UNION'
- '<script'
- 'cmd='
- '/etc/passwd'
condition: selection
falsepositives:
- Legitimate activity from CVE-2026-3039
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-3039 | DoS | BIND 9 versions 9.0.0 through 9.16.50 |
| CVE-2026-3039 | DoS | BIND 9 versions 9.18.0 through 9.18.48 |
| CVE-2026-3039 | DoS | BIND 9 versions 9.20.0 through 9.20.22 |
| CVE-2026-3039 | DoS | BIND 9 servers configured to use TKEY-based authentication via GSS-API tokens |
| CVE-2026-3039 | DoS | Excessive memory consumption from maliciously-constructed packets |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 20, 2026 at 16:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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