CoreDNS up to 1.14.2 TsigStatus incorrect implementation of authentication algorithm

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.
5.1$0-$5k0.00

Summaryinfo

A vulnerability was found in CoreDNS up to 1.14.2. It has been classified as problematic. This issue affects the function TsigStatus. Performing a manipulation results in incorrect implementation of authentication algorithm. This vulnerability was named CVE-2026-33190. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic has been found in CoreDNS up to 1.14.2. This affects the function TsigStatus. The manipulation with an unknown input leads to a incorrect implementation of authentication algorithm vulnerability. CWE is classifying the issue as CWE-303. The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect. This is going to have an impact on confidentiality. The summary by CVE is:

CoreDNS is a DNS server that chains plugins. In versions prior to 1.14.3, the tsig plugin can be bypassed on non-plain-DNS transports (DoT, DoH, DoH3, DoQ, and gRPC) because it trusts the transport writer's TsigStatus() instead of performing verification itself. The DoH and DoH3 writer's TsigStatus() always returns nil, the DoT server does not set TsigSecret on the dns.Server, and the DoQ and gRPC writers also unconditionally return nil. This allows an unauthenticated remote client to bypass TSIG-based authentication and access resources intended to be restricted behind a tsig require all policy. Plain DNS over TCP and UDP are not affected. This issue has been fixed in version 1.14.3.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-33190 since 03/17/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 313705 (openSUSE 16 Security Update : coredns (openSUSE-SU-2026:20703-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.14.3 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (313705) and EUVD (EUVD-2026-27444). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

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

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Incorrect implementation of authentication algorithm
CWE: CWE-303
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 313705
Nessus Name: openSUSE 16 Security Update : coredns (openSUSE-SU-2026:20703-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: CoreDNS 1.14.3

Timelineinfo

03/17/2026 CVE reserved
05/05/2026 +48 days Advisory disclosed
05/05/2026 +0 days VulDB entry created
05/10/2026 +5 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-33190 (🔒)
GCVE (CVE): GCVE-0-2026-33190
GCVE (VulDB): GCVE-100-361233
EUVD: 🔒

Entryinfo

Created: 05/05/2026 21:58
Updated: 05/10/2026 22:05
Changes: 05/05/2026 21:58 (65), 05/06/2026 15:57 (1), 05/10/2026 22:05 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!