CVE-2026-91373: Medium severity Oracle Java SE vulnerability

Published Oct 20, 2026
·
Updated

Vulnerability in Oracle Java SE (component: JSSE). Supported versions that are affected are Oracle Java SE: 8u503, 8u503-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1; Oracle GraalVM for JDK: 17.0.20.1 and 21.0.12.1; Oracle GraalVM Enterprise Edition: 21.3.19.1.1. Easily exploitable vulnerability allows unauthenticated attacker with network access via TLS to compromise Oracle Java SE. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Java SE. 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 5.3 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Affected Software

57 affected componentsFixes available
Oracle Java SE=8u503, =8u503-perf, =11.0.32.1, =17.0.20.1, =21.0.12.1, =25.0.4.1
Oracle GraalVM for JDK=17.0.20.1, =21.0.12.1
Oracle GraalVM Enterprise Edition=21.3.19.1.1
debian/openjdk-17<17.0.21+9-1~deb12u1
17.0.21+9-1~deb12u1
debian/openjdk-21<21.0.13+9-1~deb13u2
21.0.13+9-1~deb13u2
debian/openjdk-21<21.0.13+9-1
21.0.13+9-1
debian/openjdk-25<25.0.5+8-1~deb13u1
25.0.5+8-1~deb13u1
debian/openjdk-25<25.0.5+8-1
25.0.5+8-1
debian/openjdk-27*
alpine/openjdk17<17.0.21.0.3_p1-r0
17.0.21.0.3_p1-r0
alpine/openjdk17<17.0.21.0.3_p1-r0
17.0.21.0.3_p1-r0
alpine/openjdk21<21.0.13.0.3_p1-r0
21.0.13.0.3_p1-r0
alpine/openjdk21<21.0.13.0.3_p1-r0
21.0.13.0.3_p1-r0
alpine/openjdk25<25.0.5.0.3_p1-r0
25.0.5.0.3_p1-r0
alpine/openjdk25<25.0.5.0.3_p1-r0
25.0.5.0.3_p1-r0
debian/openjdk-11
11.0.33+9-1
debian/openjdk-17<=17.0.19+10-1~deb12u2
17.0.21+9-1~deb12u117.0.21.0.3+1-1
debian/openjdk-21<=21.0.12.1+1-1~deb13u1
21.0.13+9-1~deb13u221.0.13.0.3+1-1
debian/openjdk-25<=25.0.3+9-2~deb13u1
25.0.5+8-1~deb13u125.0.5+8-125.0.5.0.3+1-1
debian/openjdk-27<=27~34ea-1
27.0.1.0.3+1-1
debian/openjdk-8
8u512-ga-1
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~16.04.1
8u512-b09~us1-0ubuntu1~16.04.1
ubuntu/openjdk-9*
ubuntu/openjdk-lts<11.0.33+9-1ubuntu1~18.04.1
11.0.33+9-1ubuntu1~18.04.1
ubuntu/openjdk-17*
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~18.04.1
8u512-b09~us1-0ubuntu1~18.04.1
ubuntu/openjdk-lts<11.0.33+9-1ubuntu1~20.04.1
11.0.33+9-1ubuntu1~20.04.1
ubuntu/openjdk-13*
ubuntu/openjdk-16*
ubuntu/openjdk-17*
ubuntu/openjdk-21*
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~20.04.1
8u512-b09~us1-0ubuntu1~20.04.1
ubuntu/openjdk-17*
ubuntu/openjdk-21*
ubuntu/openjdk-25<25.0.5.0.3+1-1~22.04.1
25.0.5.0.3+1-1~22.04.1
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~22.04.1
8u512-b09~us1-0ubuntu1~22.04.1
ubuntu/openjdk-lts<11.0.33+9-1ubuntu1~22.04.1
11.0.33+9-1ubuntu1~22.04.1
ubuntu/openjdk-17*
ubuntu/openjdk-21*
ubuntu/openjdk-25<25.0.5.0.3+1-1~24.04.1
25.0.5.0.3+1-1~24.04.1
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~24.04.1
8u512-b09~us1-0ubuntu1~24.04.1
ubuntu/openjdk-lts<11.0.33+9-1ubuntu1~24.04.1
11.0.33+9-1ubuntu1~24.04.1
ubuntu/openjdk-17*
ubuntu/openjdk-17-crac*
ubuntu/openjdk-21*
ubuntu/openjdk-21-crac*
ubuntu/openjdk-25<25.0.5.0.3+1-1~26.10.1
25.0.5.0.3+1-1~26.10.1
ubuntu/openjdk-27<27.0.1.0.3+1-1~26.10.1
27.0.1.0.3+1-1~26.10.1
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~26.10.1
8u512-b09~us1-0ubuntu1~26.10.1
ubuntu/openjdk-lts<11.0.33+9-1ubuntu1~26.10.1
11.0.33+9-1ubuntu1~26.10.1
ubuntu/openjdk-17*
ubuntu/openjdk-17-crac*
ubuntu/openjdk-21*
ubuntu/openjdk-21-crac*
ubuntu/openjdk-25<25.0.5.0.3+1-1~26.04.1
25.0.5.0.3+1-1~26.04.1
ubuntu/openjdk-8<8u512-b09~us1-0ubuntu1~26.04.1
8u512-b09~us1-0ubuntu1~26.04.1
ubuntu/openjdk-lts<11.0.33+9-1ubuntu1~26.04.1
11.0.33+9-1ubuntu1~26.04.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/openjdk-17 to a version that resolves this vulnerability.

    Fixed in 17.0.21+9-1~deb12u1
  2. Upgrade

    Upgrade debian/openjdk-21 to a version that resolves this vulnerability.

    Fixed in 21.0.13+9-1~deb13u2
  3. Upgrade

    Upgrade debian/openjdk-21 to a version that resolves this vulnerability.

    Fixed in 21.0.13+9-1
  4. Upgrade

    Upgrade debian/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5+8-1~deb13u1
  5. Upgrade

    Upgrade debian/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5+8-1
  6. Upgrade

    Upgrade alpine/openjdk17 to a version that resolves this vulnerability.

    Fixed in 17.0.21.0.3_p1-r0
  7. Upgrade

    Upgrade alpine/openjdk21 to a version that resolves this vulnerability.

    Fixed in 21.0.13.0.3_p1-r0
  8. Upgrade

    Upgrade alpine/openjdk25 to a version that resolves this vulnerability.

    Fixed in 25.0.5.0.3_p1-r0
  9. Upgrade

    Upgrade debian/openjdk-11 to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1
  10. Upgrade

    Upgrade debian/openjdk-17 to a version that resolves this vulnerability.

    Fixed in 17.0.21+9-1~deb12u1Fixed in 17.0.21.0.3+1-1
  11. Upgrade

    Upgrade debian/openjdk-21 to a version that resolves this vulnerability.

    Fixed in 21.0.13+9-1~deb13u2Fixed in 21.0.13.0.3+1-1
  12. Upgrade

    Upgrade debian/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5+8-1~deb13u1Fixed in 25.0.5+8-1Fixed in 25.0.5.0.3+1-1
  13. Upgrade

    Upgrade debian/openjdk-27 to a version that resolves this vulnerability.

    Fixed in 27.0.1.0.3+1-1
  14. Upgrade

    Upgrade debian/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-ga-1
  15. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~16.04.1
  16. Upgrade

    Upgrade ubuntu/openjdk-lts to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1ubuntu1~18.04.1
  17. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~18.04.1
  18. Upgrade

    Upgrade ubuntu/openjdk-lts to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1ubuntu1~20.04.1
  19. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~20.04.1
  20. Upgrade

    Upgrade ubuntu/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5.0.3+1-1~22.04.1
  21. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~22.04.1
  22. Upgrade

    Upgrade ubuntu/openjdk-lts to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1ubuntu1~22.04.1
  23. Upgrade

    Upgrade ubuntu/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5.0.3+1-1~24.04.1
  24. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~24.04.1
  25. Upgrade

    Upgrade ubuntu/openjdk-lts to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1ubuntu1~24.04.1
  26. Upgrade

    Upgrade ubuntu/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5.0.3+1-1~26.10.1
  27. Upgrade

    Upgrade ubuntu/openjdk-27 to a version that resolves this vulnerability.

    Fixed in 27.0.1.0.3+1-1~26.10.1
  28. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~26.10.1
  29. Upgrade

    Upgrade ubuntu/openjdk-lts to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1ubuntu1~26.10.1
  30. Upgrade

    Upgrade ubuntu/openjdk-25 to a version that resolves this vulnerability.

    Fixed in 25.0.5.0.3+1-1~26.04.1
  31. Upgrade

    Upgrade ubuntu/openjdk-8 to a version that resolves this vulnerability.

    Fixed in 8u512-b09~us1-0ubuntu1~26.04.1
  32. Upgrade

    Upgrade ubuntu/openjdk-lts to a version that resolves this vulnerability.

    Fixed in 11.0.33+9-1ubuntu1~26.04.1

Event History

Oct 20, 2026
CVE Published
via MITRE·09:25 PM
Data Sourced
via MITRE·09:25 PM
DescriptionSeverity
Data Sourced
via OSV·10:20 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·10:20 PM
DescriptionSeverityWeakness
Oct 21, 2026
Data Sourced
via Red Hat·12:02 AM
DescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

Which deployments are realistically exposed to network-based exploitation?

Oracle Java SE deployments that use JSSE and are reachable by an attacker over TLS are exposed. The issue can also be reached indirectly through a web service that supplies attacker-controlled data to the affected APIs.

2

Does exploitation require credentials, user interaction, or a complex attack setup?

No. The vulnerability is described as easily exploitable by an unauthenticated attacker with network access via TLS, and the CVSS vector specifies low attack complexity with no privileges or user interaction required.

3

What is the expected impact of a successful attack?

A successful attack can cause a partial denial of service in Oracle Java SE. The stated CVSS impacts are limited to availability; no confidentiality or integrity impact is listed.

4

Are sandboxed Java client deployments in scope?

Yes, where they load and run untrusted code and rely on the Java sandbox for security. The description specifically identifies sandboxed Java Web Start applications and sandboxed Java applets as affected deployment scenarios.

5

Which upstream releases are identified as affected?

The affected Oracle Java SE releases are 8u503, 8u503-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, and 25.0.4.1. Affected GraalVM releases are 17.0.20.1 and 21.0.12.1 for GraalVM for JDK, and 21.3.19.1.1 for GraalVM Enterprise Edition.

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