VDB-370595 · CVE-2026-45673 · WID-SEC-2026-1814

Netty prior 4.1.135.Final/4.2.15.Final DNS Transaction ID random values

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.
5.2	$0-$5k	3.15-

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Netty. Impacted is an unknown function of the component DNS Transaction ID Handler. The manipulation leads to random values. This vulnerability is referenced as CVE-2026-45673. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Netty. This issue affects an unknown functionality of the component DNS Transaction ID Handler. The manipulation with an unknown input leads to a random values vulnerability. Using CWE to declare the problem leads to CWE-330. The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers. Impacted is confidentiality. The summary by CVE is:

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, Netty's DNS resolver uses a predictable PRNG for generating DNS transaction IDs and defaults to a static UDP source port. This combination reduces the entropy of DNS queries, enabling DNS Cache Poisoning (Kaminsky attack). Versions 4.1.135.Final and 4.2.15.Final patch the issue.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-45673 since 05/12/2026. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1600.001 according to MITRE ATT&CK.

Upgrading to version 4.1.135.Final or 4.2.15.Final eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1814). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

Open Source Netty

Productinfo

Name

Netty

Website

Product: https://github.com/netty/netty/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.2
VulDB Meta Temp Score: 5.2

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.8
CNA Vector (GitHub_M): 🔒

CVSSv2info

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

Exploitinginfo

Class: Random values
CWE: CWE-330 / CWE-310
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Netty 4.1.135.Final/4.2.15.Final

Timelineinfo

05/12/2026 CVE reserved
06/12/2026 +31 days Advisory disclosed
06/12/2026 +0 days VulDB entry created
06/13/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-45673 (🔒)
GCVE (CVE): GCVE-0-2026-45673
GCVE (VulDB): GCVE-100-370595
CERT Bund: WID-SEC-2026-1814 - Netty: Mehrere Schwachstellen

Entryinfo

Created: 06/12/2026 17:15
Updated: 06/13/2026 00:33
Changes: 06/12/2026 17:15 (62), 06/13/2026 00:33 (7)
Complete: 🔍
Cache ID: 216::103

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