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Full vulnerability report · 2026
CVE-2026-47040High confidence

Vulnerability in the Oracle Net Services component of Oracle Database Server

Oracle Corporation · Oracle Net Services

9.1CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.49% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Oracle Corporation Oracle Net Services and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-46527

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Mitigation available
01

What, why and how

Vulnerability in the Oracle Net Services component of Oracle Database Server. Supported versions that are affected are 19.3-19.31, 21.3-21.22 and 23.4.0-23.26.2. Easily exploitable vulnerability allows unauthenticated attacker with network access via Oracle Net to compromise Oracle Net Services. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Net Services accessible data and unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Net Services. CVSS 3.1 Base Score 9.1 (Confidentiality and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).

What

Vulnerability in the Oracle Net Services component of Oracle Database Server. Supported versions that are affected are 19.3-19.31, 21.3-21.22 and 23.4.0-23.26.2. Easily exploitable vulnerability allows unauthenticated attacker with network access via Oracle Net to compromise Oracle Net Services. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Net Services accessible data and unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Net Services. CVSS 3.1 Base Score 9.1 (Confidentiality and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).

Why

A security-sensitive function is reachable without the authentication check that should protect it.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

Vulnerability in the Oracle Net Services component of Oracle Database Server. Supported versions that are affected are 19.3-19.31, 21.3-21.22 and 23.4.0-23.26.2. Easily exploitable vulnerability allows unauthenticated attacker with network access via Oracle Net to compromise Oracle Net Services. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Net Services accessible data and unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Net Services. CVSS 3.1 Base Score 9.1 (Confidentiality and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H).

Why

A security-sensitive function is reachable without the authentication check that should protect it.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Missing Authentication for Critical Function → disrupt the affected service
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-306 ↗

CWE-306: Missing Authentication for Critical Function. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedDenial of serviceCWE-306
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-2430Oracle Database Server: Mehrere Schwachstellen

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Database Server ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0914Multiples vulnérabilités dans Oracle Database Server

d?id=CVE-2026-42768 Référence CVE CVE-2026-42769 https://www.cve.org/CVERecord?id=CVE-2026-42769 Référence CVE CVE-2026-42770 https://www.cve.org/CVERecord?id=CVE-2026-42770 Référence CVE CVE-2026-45445 https://www.cve.org/CVERecord?id=CVE-2026-45445 Référence CVE CVE-2026-45446 https://www.cve.org/CVERecord?id=CVE-2026-45446 Référence CVE CVE-2026-45447 https://www.cve.org/CVERecord?id=CVE-2026-45447 Référence CVE CVE-2026-46975 https://www.cve.org/CVERecord?id=CVE-2026-46975 Référence CVE CVE-2026-47038 https://www.cve.org/CVERecord?id=CVE-2026-47038 Référence CVE CVE-2026-47039 https://www.cve.org/CVERecord?id=CVE-2026-47039 Référence CVE CVE-2026-47040 https://www.cve.org/CVERecord?id=CVE-2026-47040 Référence CVE CVE-2026-47045 https://www.cve.org/CVERecord?id=CVE-2026-47045 Référence CVE CVE-2026-47046 https://www.cve.org/CVERecord?id=CVE-2026-47046 Référence CVE CVE-2026-47060 https://www.cve.org/CVERecord?id=CVE-2026-47060 Référence CVE CVE-2026-47061 https://www.cve.org/CVERecord?id=CVE-2026-47061 Référence CVE CVE-2026-4738 https://www.cve.org/CVERecord?id=CVE-2026-4738 Référence CVE CVE-2026-54512 https://www.cve.org/CVERecord?id=CVE-2026-54512 Référence CVE CVE-2026-54513 https://www.cve.org/CVERecord?id=CVE-2026-54513 Référence CVE CVE-2026-54514 https://www.cve.org/CVERecord?id=CV

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-027428オラクルのOracle Databaseにおける重要な機能に対する認証の欠如に関する脆弱性

Oracle Database ServerのOracle Net Servicesコンポーネントにおける脆弱性です。影響を受けるサポート対象バージョンは19.3から19.31、21.3から21.22、および23.4.0から23.26.2です。容易に悪用可能な脆弱性により、認証されていない攻撃者がOracle Netを介してネットワークアクセスを行い、Oracle Net Servicesを侵害することが可能です。この脆弱性を悪用すると、重要なデータへの不正アクセスが発生したり、アクセス可能なすべてのOracle Net Servicesのデータに完全にアクセスできるようになったり、Oracle Net Servicesがハングしたり頻繁にクラッシュ（完全なサービス拒否: DoS）するなどの影響が生じます。CVSS 3.1基本スコアは9.1（機密性および可用性に影響）です。CVSSベクター：(CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H)

Official advisory ↗
NCSC-NL · Dutch · NCSC-2026-0254Kwetsbaarheden verholpen in Oracle database producten

A critical vulnerability in Oracle Net Services versions 19.3-19.31, 21.3-21.22, and 23.4.0-23.26.2 allows unauthenticated network attackers to gain unauthorized access or cause denial of service, with a CVSS 3.1 base score of 9.1.

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
Oracle Net Services: 19.3 ≤ 19.31, 21.3 ≤ 21.22, 23.4.0 ≤ 23.26.2
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Oracle heeft updates uitgebracht om de kwetsbaarheden te verhelpen. Voor Apache Kafka wordt aanbevolen te upgraden naar versie 4.1.2 of hoger en de JWT validator expliciet in te stellen. Voor Perl is een update van de Compress::Raw::Zlib module beschikbaar in de nieuwste versies. Zie bijgevoegde referenties voor meer informatie.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 21 Jul 2026 · Last source change 23 Jul 2026, 15:37 UTC · CWE-306 · Missing Authentication for Critical Function

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-46527
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    NCSC-NL ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Remediation guidance recorded
ENISA EUVD · EUVD-2026-46527↗NCSC-NL remediation guidance↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-47040 · cve.blacktree.nl