How severe is CVE-2026-21926?

CVE-2026-21926 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-21926 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21926?

CVE-2026-21926 affects Oracle Siebel Customer Relationship Management Deployment. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21926?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-21926 have an EU (EUVD) identifier?

Yes. CVE-2026-21926 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3583.

When was CVE-2026-21926 published?

CVE-2026-21926 was published on 2026-01-20 and last updated on 2026-06-17.

CVE-2026-21926

CVE-2026-21926 is a high-severity vulnerability in Oracle Siebel Customer Relationship Management Deployment with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-3583
Affected product: Oracle Siebel Customer Relationship Management Deployment
Published: 2026-01-20
Last modified: 2026-06-17

Description

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).

Frequently asked questions

What is CVE-2026-21926?: 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).
How severe is CVE-2026-21926?: CVE-2026-21926 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-21926 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21926?: CVE-2026-21926 affects Oracle Siebel Customer Relationship Management Deployment. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21926?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-21926 have an EU (EUVD) identifier?: Yes. CVE-2026-21926 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3583.
When was CVE-2026-21926 published?: CVE-2026-21926 was published on 2026-01-20 and last updated on 2026-06-17.

References

https://www.oracle.com/security-alerts/cpujan2026.html

Affected products (1)

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