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CVE Record

CVE-2026-21925: 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: RMI). 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. Difficult to exploit 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 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 4.8 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N).

MediumCVSS 4.8Not 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 and GraalVM issue in the RMI component. A remote unauthenticated attacker could, under difficult conditions, read or change limited accessible data. The main concern is exposed Java services or legacy sandboxed Java clients that rely on Java’s sandbox for untrusted code.

Executive priority

Treat as a normal patch-cycle priority unless affected Java services are exposed or legacy sandboxed Java is still in use. Those environments should be prioritized because the attack is remote and unauthenticated despite high complexity.

Technical view

CVE-2026-21925 affects listed Oracle Java SE, GraalVM for JDK, and GraalVM Enterprise Edition versions. Oracle describes network exploitation over multiple protocols with high attack complexity, no privileges, and no user interaction. Impact is limited confidentiality and integrity, with no availability impact, reflected by CVSS 3.1 score 4.8.

Likely exposure

Exposure is most likely where affected Java or GraalVM versions are used by network-facing services invoking RMI/component APIs, or where legacy Java Web Start/applets run untrusted code under sandbox assumptions.

Exploitation context

The provided bundle does not report active exploitation, and KEV status is false. Oracle states exploitation is difficult but unauthenticated and network reachable. The note indicates possible exploitation through APIs, including web services supplying data to the affected component.

Researcher notes

Sources identify RMI as the affected component but do not provide root-cause detail, exploit primitives, or fixed version mapping in the bundle. Avoid assuming exploitability beyond Oracle’s note on component APIs and untrusted sandboxed Java deployments.

Mitigation direction

  • Follow Oracle CPU January 2026 guidance for patched or supported replacement versions.
  • Inventory Oracle Java SE and GraalVM versions against the affected release list.
  • Review Siemens SSA-032379 if Siemens environments may depend on affected Java components.
  • Restrict network access to RMI or Java services where business requirements allow.
  • Retire sandboxed Java Web Start or applet usage that loads untrusted code.

Validation and detection

  • Confirm installed Java and GraalVM versions match or exceed vendor-fixed guidance.
  • Identify applications using RMI or APIs in the affected component.
  • Review internet-facing services for Java endpoints that supply data to RMI-related APIs.
  • Check endpoint and server inventories for Java Web Start or applet dependencies.
  • Document any Siemens advisory applicability before accepting residual risk.
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-2026-21925 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
4.8 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/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
4.8CVSS 3.1MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N2.22.5oracle

Vulnerability scoring details

Base CVSS 3.1 score

4.8Medium
CVSS 3.1 vector shape for CVE-2026-21925Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/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.