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CVE Record

CVE-2026-21933: Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of O...

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Networking). Supported versions that are affected are Oracle Java SE: 8u471, 8u471-b50, 8u471-perf, 11.0.29, 17.0.17, 21.0.9, 25.0.1; Oracle GraalVM for JDK: 17.0.17 and 21.0.9; Oracle GraalVM Enterprise Edition: 21.3.16. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks require human interaction from a person other than the attacker and while the vulnerability is in Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition, attacks may significantly impact additional products (scope change). Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data as well as unauthorized read access to a subset of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 6.1 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

MediumCVSS 6.1Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a medium-severity Oracle Java/GraalVM networking vulnerability. An unauthenticated network attacker could trigger it through multiple protocols, but a separate user must interact. Successful exploitation can read or change some data accessible to the affected runtime, and impact may extend to products using it.

Executive priority

Treat this as a scheduled security update with targeted urgency for internet-facing Java services and legacy client Java deployments. It is not marked as actively exploited in the provided sources, but it affects widely deployed runtimes.

Technical view

CVE-2026-21933 affects listed Oracle Java SE, GraalVM for JDK, and GraalVM Enterprise Edition versions in the Networking component. CVSS is 6.1 with network access, low complexity, no privileges, required user interaction, changed scope, and low confidentiality and integrity impact.

Likely exposure

Exposure is most likely where affected Java or GraalVM builds process attacker-influenced networking data, including web services supplying data to relevant APIs. Client-side sandboxed Java Web Start or applet deployments that load untrusted code are also called out.

Exploitation context

The source bundle does not show CISA KEV listing or confirmed active exploitation. Oracle describes the issue as easily exploitable over the network, but requiring human interaction by someone other than the attacker.

Researcher notes

Oracle notes exploitation may occur through APIs in the Networking component, including data supplied by web services. The CVE does not provide CWE, root-cause detail, proof of concept, fixed versions, or product-specific Siemens details in the supplied bundle.

Mitigation direction

  • Check Oracle’s January 2026 CPU for fixed Java and GraalVM builds.
  • Prioritize replacing affected Java SE and GraalVM versions listed in the CVE.
  • Review Siemens SSA-032379 if Siemens products are in scope.
  • Reduce exposure of services passing untrusted network data into Java Networking APIs.
  • Avoid relying on Java sandboxing for untrusted internet-sourced code.

Validation and detection

  • Inventory Java SE and GraalVM runtime versions across servers, desktops, and build images.
  • Flag versions matching 8u471, 11.0.29, 17.0.17, 21.0.9, 25.0.1, or listed GraalVM builds.
  • Identify applications using Java Networking APIs with externally supplied data.
  • Check for legacy Java Web Start or applet use with untrusted code.
  • Confirm vendor advisories for embedded or third-party Java runtimes.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2026-21933 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.1 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
2ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.1CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N2.82.7oracle

Vulnerability scoring details

Base CVSS 3.1 score

6.1Medium
CVSS 3.1 vector shape for CVE-2026-21933Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Oracle CorporationOracle Java SE8u471, 8u471-b50, 8u471-perf, 11.0.29, 17.0.17, 21.0.9, 25.0.1Listed
Oracle CorporationOracle GraalVM for JDK17.0.17, 21.0.9Listed
Oracle CorporationOracle GraalVM Enterprise Edition21.3.16Listed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.