CVE-2026-91403: Critical severity Oracle Java SE vulnerability

Published Oct 21, 2026
·
Updated

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: JSSE). Supported versions that are affected are Oracle Java SE: 8u511, 8u511-perf, 11.0.33, 17.0.21, 21.0.13, 25.0.5, 27.0.1; Oracle GraalVM for JDK: 17.0.21 and 21.0.13; Oracle GraalVM Enterprise Edition: 21.3.20. 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 creation, deletion or modification access to critical data or all Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data as well as unauthorized access to critical data or complete access to all Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability can be exploited by using APIs in th

Affected Software

38 affected componentsFixes available
Oracle Java SE=8u511, =8u511-perf, =11.0.33, =17.0.21, =21.0.13, =25.0.5, =27.0.1
Oracle GraalVM for JDK=17.0.21, =21.0.13
Oracle GraalVM Enterprise Edition=21.3.20
debian/openjdk-17*
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~deb12u1
17.0.21.0.3+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-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-8<8u512-b09~us1-0ubuntu1~20.04.1
8u512-b09~us1-0ubuntu1~20.04.1
ubuntu/openjdk-18*
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-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-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-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-21 to a version that resolves this vulnerability.

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

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

    Fixed in 21.0.13+9-1
  3. Upgrade

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

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

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

    Fixed in 25.0.5+8-1
  5. Upgrade

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

    Fixed in 17.0.21.0.3_p1-r0
  6. Upgrade

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

    Fixed in 21.0.13.0.3_p1-r0
  7. Upgrade

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

    Fixed in 25.0.5.0.3_p1-r0
  8. Upgrade

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

    Fixed in 11.0.33+9-1
  9. Upgrade

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

    Fixed in 17.0.21.0.3+1-1
  10. 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
  11. 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
  12. Upgrade

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

    Fixed in 27.0.1.0.3+1-1
  13. Upgrade

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

    Fixed in 8u512-ga-1
  14. Upgrade

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    Fixed in 8u512-b09~us1-0ubuntu1~26.04.1
  26. 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 21, 2026
CVE Published
via MITRE·09:23 PM
Data Sourced
via MITRE·09:23 PM
DescriptionSeverity
Data Sourced
via Red Hat·09:45 PM
DescriptionSeverityAffected Software
Data Sourced
via OSV·10:16 PM
DescriptionSeverityAffected Software
Data Sourced
via NVD·10:16 PM
DescriptionSeverityWeakness
Oct 22, 2026
Exploit Published
via GitHub·07:25 PM
Oct 25, 2026
Data Sourced
via Microsoft·08:02 AM
DescriptionSeverityWeakness

Parent advisories

This vulnerability appears in the following advisories.

Frequently Asked Questions

1

Which deployments are exposed to remote exploitation?

Deployments running the listed affected releases of Oracle Java SE, Oracle GraalVM for JDK, or Oracle GraalVM Enterprise Edition are exposed if an attacker can reach them over the network via one of the applicable protocols.

2

Does exploitation require credentials or user interaction?

No. The vulnerability is described as easily exploitable by an unauthenticated attacker with network access, with no user interaction required.

3

What could an attacker gain after successful exploitation?

A successful attack can allow unauthorized creation, deletion, or modification of critical data or all accessible product data. It can also allow unauthorized access to critical data or complete access to all accessible product data.

4

Which releases should be checked during asset inventory?

Check for Oracle Java SE 8u511, 8u511-perf, 11.0.33, 17.0.21, 21.0.13, 25.0.5, and 27.0.1; Oracle GraalVM for JDK 17.0.21 and 21.0.13; and Oracle GraalVM Enterprise Edition 21.3.20.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203