CVE-2026-73508
Description
A flaw was found in Netty, an asynchronous network application framework. When processing malformed domain names in DNS packets, the DNS record decoder fails to release allocated memory. This vulnerability allows an unauthenticated remote attacker to incrementally leak direct memory, eventually leading to a denial of service.
Statement
This flaw is rated Important because the affected component fails to release allocated memory when it rejects a malformed domain name during DNS record decoding. An unauthenticated remote attacker who can send DNS traffic to an application using the affected DNS resolution functionality can incrementally exhaust available memory until the process becomes unresponsive, resulting in a complete denial of service.
Mitigation
Red Hat recommends upgrading to a fixed version as the primary remediation. Where an immediate upgrade is not possible, restrict network access so that only trusted DNS servers and trusted network peers can send DNS traffic to the affected application, using firewall or network policy rules to block or rate-limit DNS traffic from untrusted sources. This reduces exposure to the malformed DNS records that trigger the issue but does not fully eliminate it; upgrading remains the only complete fix.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.5 | 5.3 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Other); DoS: Resource Consumption (Memory); DoS: Resource Consumption (CPU)
An attacker that can influence the allocation of resources that are not properly released could deplete the available resource pool and prevent all other processes from accessing the same type of resource. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Frequently Asked Questions
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