VDB-342101 · CVE-2026-21926 · EUVD-2026-3583

Oracle Siebel CRM Deployment up to 25.2 Server Infrastructure denial of service

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 marked as problematic has been reported in Oracle Siebel CRM Deployment up to 25.2. Affected by this issue is some unknown functionality of the component Server Infrastructure. The manipulation leads to denial of service. This vulnerability is documented as CVE-2026-21926. The attack can be initiated remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Oracle Siebel CRM Deployment up to 25.2. This issue affects an unknown code of the component Server Infrastructure. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

Vulnerability in the Siebel CRM Deployment product of Oracle Siebel CRM (component: Server Infrastructure). Supported versions that are affected are 17.0-25.2. Easily exploitable vulnerability allows unauthenticated attacker with network access via TLS to compromise Siebel CRM Deployment. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Siebel CRM Deployment. CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

The advisory is shared at oracle.com. The identification of this vulnerability is CVE-2026-21926 since 01/05/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful 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 294866 (Oracle Siebel Server <= 25.2 (January 2026 CPU)), 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 (294866) and EUVD (EUVD-2026-3583). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Customer Relationship Management System

Vendor

Oracle

Name

Siebel CRM Deployment

Version

License

commercial

Website

Vendor: https://www.oracle.com

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 (oracle): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Denial of service
CWE: CWE-404
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

Nessus ID: 294866
Nessus Name: Oracle Siebel Server <= 25.2 (January 2026 CPU)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

01/05/2026 CVE reserved
01/20/2026 +15 days Advisory disclosed
01/20/2026 +0 days VulDB entry created
01/22/2026 +2 days VulDB entry last update

Sourcesinfo

Vendor: oracle.com

Advisory: oracle.com
Status: Confirmed

CVE: CVE-2026-21926 (🔒)
GCVE (CVE): GCVE-0-2026-21926
GCVE (VulDB): GCVE-100-342101
EUVD: 🔒

Entryinfo

Created: 01/20/2026 23:52
Updated: 01/22/2026 14:32
Changes: 01/20/2026 23:52 (64), 01/21/2026 13:15 (1), 01/22/2026 14:32 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.