CVE-2026-21945: 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 of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. in Oracle Corporation Oracle Java SE
Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Security). 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 of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Note: This vulnerability 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. This vulnerability does not apply to Java deployments, typically in servers, that load and run only trusted code (e.g., code installed by an administrator). CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
AI Analysis
Technical Summary
CVE-2026-21945 is a vulnerability in the security component of Oracle Java SE, Oracle GraalVM for JDK, and Oracle GraalVM Enterprise Edition. It affects specific versions including Oracle Java SE 8u471, 8u471-b50, 8u471-perf, 11.0.29, 17.0.17, 21.0.9, and 25.0.1; Oracle GraalVM for JDK 17.0.17 and 21.0.9; and Oracle GraalVM Enterprise Edition 21.3.16. The flaw allows an unauthenticated attacker with network access via multiple protocols to cause a denial of service by hanging or crashing the affected Java runtime. This vulnerability is relevant to client-side Java deployments that execute untrusted code within sandboxed environments but does not apply to server-side deployments running only trusted code. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) reflects a network attack vector with low complexity, no privileges or user interaction required, and a high impact on availability. Oracle's January 2026 Critical Patch Update includes fixes for this vulnerability, and Oracle strongly recommends applying these patches without delay.
Potential Impact
Successful exploitation of this vulnerability allows an unauthenticated attacker with network access to cause a hang or frequent crash of the affected Oracle Java SE and GraalVM products, resulting in a complete denial of service. There is no impact on confidentiality or integrity. The vulnerability affects client-side Java deployments that run untrusted code in sandboxed environments, such as Java Web Start applications or applets. Server-side deployments running only trusted code are not affected.
Mitigation Recommendations
Oracle has released a Critical Patch Update in January 2026 that addresses this vulnerability among others. Customers should apply the Oracle Critical Patch Update security patches promptly to remediate this issue. Oracle strongly recommends remaining on actively supported versions and applying patches without delay. Patch availability and installation instructions are provided in the Oracle advisory at https://www.oracle.com/security-alerts/cpujan2026.html. No alternative mitigations or workarounds are specified in the advisory.
CVE-2026-21945: 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 of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. in Oracle Corporation Oracle Java SE
Description
Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Security). 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 of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Note: This vulnerability 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. This vulnerability does not apply to Java deployments, typically in servers, that load and run only trusted code (e.g., code installed by an administrator). CVSS 3.1 Base Score 7.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).
CVSS v3.1
Score 7.5high
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-21945 is a vulnerability in the security component of Oracle Java SE, Oracle GraalVM for JDK, and Oracle GraalVM Enterprise Edition. It affects specific versions including Oracle Java SE 8u471, 8u471-b50, 8u471-perf, 11.0.29, 17.0.17, 21.0.9, and 25.0.1; Oracle GraalVM for JDK 17.0.17 and 21.0.9; and Oracle GraalVM Enterprise Edition 21.3.16. The flaw allows an unauthenticated attacker with network access via multiple protocols to cause a denial of service by hanging or crashing the affected Java runtime. This vulnerability is relevant to client-side Java deployments that execute untrusted code within sandboxed environments but does not apply to server-side deployments running only trusted code. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) reflects a network attack vector with low complexity, no privileges or user interaction required, and a high impact on availability. Oracle's January 2026 Critical Patch Update includes fixes for this vulnerability, and Oracle strongly recommends applying these patches without delay.
Potential Impact
Successful exploitation of this vulnerability allows an unauthenticated attacker with network access to cause a hang or frequent crash of the affected Oracle Java SE and GraalVM products, resulting in a complete denial of service. There is no impact on confidentiality or integrity. The vulnerability affects client-side Java deployments that run untrusted code in sandboxed environments, such as Java Web Start applications or applets. Server-side deployments running only trusted code are not affected.
Mitigation Recommendations
Oracle has released a Critical Patch Update in January 2026 that addresses this vulnerability among others. Customers should apply the Oracle Critical Patch Update security patches promptly to remediate this issue. Oracle strongly recommends remaining on actively supported versions and applying patches without delay. Patch availability and installation instructions are provided in the Oracle advisory at https://www.oracle.com/security-alerts/cpujan2026.html. No alternative mitigations or workarounds are specified in the advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- oracle
- Date Reserved
- 2026-01-05T18:07:34.712Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.oracle.com/security-alerts/cpujan2026.html","vendor":"Oracle"}]
Threat ID: 696ffc4a4623b1157c519f89
Added to database: 01/20/2026, 22:06:02 UTC
Last enriched: 07/31/2026, 12:59:53 UTC
Last updated: 09/10/2026, 19:36:52 UTC
Views: 646
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