How severe is CVE-2026-21999?

CVE-2026-21999 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-21999 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21999?

CVE-2026-21999 affects Oracle Xml Database. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21999?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-21999 have an EU (EUVD) identifier?

Yes. CVE-2026-21999 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24297.

When was CVE-2026-21999 published?

CVE-2026-21999 was published on 2026-04-21 and last updated on 2026-07-08.

CVE-2026-21999

CVE-2026-21999 is a medium-severity vulnerability in Oracle Xml Database with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-24297
Weakness: CWE-200
Affected product: Oracle Xml Database
Published: 2026-04-21
Last modified: 2026-07-08

Description

Vulnerability in the XML Database component of Oracle Database Server. Supported versions that are affected are 23.4.0-23.26.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via HTTPS to compromise XML Database. Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all XML Database accessible data. CVSS 3.1 Base Score 5.3 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N).

Frequently asked questions

What is CVE-2026-21999?: Vulnerability in the XML Database component of Oracle Database Server. Supported versions that are affected are 23.4.0-23.26.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via HTTPS to compromise XML Database. Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all XML Database accessible data. CVSS 3.1 Base Score 5.3 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N).
How severe is CVE-2026-21999?: CVE-2026-21999 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-21999 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21999?: CVE-2026-21999 affects Oracle Xml Database. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21999?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-21999 have an EU (EUVD) identifier?: Yes. CVE-2026-21999 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24297.
When was CVE-2026-21999 published?: CVE-2026-21999 was published on 2026-04-21 and last updated on 2026-07-08.

References

https://www.oracle.com/security-alerts/cpuapr2026.html

Affected products (1)

cpe:2.3:a:oracle:xml_database:*:*:*:*:*:*:*:*

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