VulnerabilityPublished 20 Jan 2026Updated 12 May 2026

CVE-2026-21933: Oracle Java SE · Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple

Affects Oracle Java SESource CVE Database V5

Not known to be exploited · CVSS 6.1 Medium.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 3.1 base score

6.1Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 22% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Oracle CorporationOracle Java SE	Affected 8u471 – 25.0.1 7 affected builds	Fixed in–
Oracle CorporationOracle GraalVM for JDK	Affected =17.0.17 =21.0.9	Fixed in–
Oracle CorporationOracle GraalVM Enterprise Edition	Affected =21.3.16	Fixed in–
Mavencom.oracle/java-se`pkg:maven/com.oracle/java-se`Other threats	Affected 11.0.29 – 25.0.1 4 affected builds	Fixed in–

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AI-suggested

Oracle has released security patches for this vulnerability as part of the January 2026 Critical Patch Update. Customers should apply these patches promptly to mitigate the risk. Oracle strongly recommends running actively supported versions and applying Critical Patch Updates without delay. No alternative mitigations or workarounds are specified in the advisory. Patch status is confirmed by the vendor advisory at https://www.oracle.com/security-alerts/cpujan2026.html.

Description

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).

Impact

Successful exploitation allows unauthorized update, insertion, deletion, and reading of some data accessible by Oracle Java SE, Oracle GraalVM for JDK, and Oracle GraalVM Enterprise Edition. This compromises confidentiality and integrity of data within the affected products. The attack requires network access and user interaction from a third party, and the scope of impact may extend beyond the initially affected products. There is no impact on availability. No known exploits in the wild have been reported at this time.

Summary

This vulnerability affects Oracle Java SE (versions 8u471, 11.0.29, 17.0.17, 21.0.9, 25.0.1), Oracle GraalVM for JDK (17.0.17, 21.0.9), and Oracle GraalVM Enterprise Edition (21.3.16). It resides in the Networking component and allows an unauthenticated attacker with network access to exploit it via multiple protocols, requiring user interaction from a third party. Successful exploitation can result in unauthorized modification (update, insert, delete) and unauthorized read access to some data accessible by these products. The vulnerability can be exploited through APIs, including web services and sandboxed Java Web Start applications or applets that load untrusted code. The CVSS vector indicates network attack vector, low attack complexity, no privileges required, user interaction required, scope changed, low confidentiality and integrity impact, and no availability impact. Oracle's January 2026 Critical Patch Update includes patches addressing this vulnerability.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 May 2026, 02:39 UTC

Technical details

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