Skip to main content

TLS CVE-2026-21926

HIGH
2026-01-20 secalert_us@oracle.com
7.5
CVSS 3.1 · NVD
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Send malicious TLS message
  2. Exploit
    Trigger resource exhaustion in server
  3. Impact
    Cause denial of service

Vulnerability Assessment

Exploitation Conditions

Network access to Siebel CRM Deployment versions 17.0–25.2 via TLS port. No authentication or special configuration required for remote unauthenticated exploitation.

Impact

CVSS 7.5 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. Exploitation no authentication required. Exploitable via remote/network.

Exploit ScenarioDerived

A remote attacker without authentication could exploit this vulnerability to unauthorized ability to cause a hang or frequently repeatable crash (complete DO.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
No patch listed yet 0.1% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Mar 12, 2026

Siebel Customer Relationship Management Deployment contains a vulnerability that allows attackers to unauthorized ability to cause a hang or frequently repeatable crash (complete DO (CVSS 7.5).

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

affects Siebel Customer Relationship Management Deployment. 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 impact

Know when TLS gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

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).

Executive ViewAI

Why It Matters

CVE-2026-21926 presents notable security risk rated CVSS 7.5. Exploitation could compromise the security of affected deployments. Organizations should apply vendor updates when available and consider compensating controls in the interim.

Business Impact: High
Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Implement network-level access controls to limit exposure; (2) Enable enhanced monitoring and alerting; (3) Apply principle of least privilege.

Threat Intelligence Overview

EPSS Score
0.1%
Top 84% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.1%
Patch available No
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
High

Priority Score

38
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:a:oracle:siebel_customer_relationship_management_deployment:*:*:*:*:*:*:*:*

More in TLS

View all
CVE-2026-27180 CRITICAL POC
9.8 Feb 18

MajorDoMo home automation platform is vulnerable to unauthenticated remote code execution through supply chain compromis

CVE-2026-27944 CRITICAL POC
9.8 Mar 05

Unauthenticated backup download and RCE in Nginx UI before 2.3.3. EPSS 1.0%. PoC available.

CVE-2026-27590 CRITICAL POC
9.8 Feb 24

FastCGI path splitting vulnerability in Caddy before 2.11.1 allows request smuggling or path confusion when proxying to

CVE-2026-27586 CRITICAL POC
9.1 Feb 24

TLS error swallowing in Caddy web server before 2.11.1 allows bypassing client certificate authentication. Errors in Cli

CVE-2026-27588 CRITICAL POC
9.1 Feb 24

Host header case sensitivity bypass in Caddy before 2.11.1. Virtual host routing can be bypassed by using alternate casi

CVE-2026-27587 CRITICAL POC
9.1 Feb 24

Case sensitivity bypass in Caddy web server path matching before 2.11.1. HTTP path matchers can be bypassed using altern

CVE-2026-25160 CRITICAL POC
9.1 Feb 04

Alist file manager has an improper certificate validation vulnerability allowing MITM attacks that could compromise file

CVE-2026-30851 HIGH POC
8.1 Mar 07

Caddy versions 2.10.0 through 2.11.1 fail to strip client-supplied headers in the forward_auth copy_headers directive, e

CVE-2022-40620 HIGH POC
7.7 Jan 28

FunJSQ, a third-party module integrated on some NETGEAR routers and Orbi WiFi Systems, does not properly validate TLS ce

CVE-2026-30852 HIGH POC
7.5 Mar 07

Caddy versions 2.7.5 through 2.11.1 contain a template injection vulnerability in the vars_regexp matcher that allows re

CVE-2026-25961 HIGH POC
7.5 Feb 09

SumatraPDF versions 3.5.0 through 3.5.2 fail to validate TLS certificates during software updates and execute installers

CVE-2025-68133 HIGH POC
7.4 Jan 21

EVerest is an EV charging software stack. In versions 2025.9.0 and below, an attacker can exhaust the operating system's

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy