HIGH

CVE-2026-21945

openjdk: Enhance Certificate Checking (Oracle CPU 2026-01)

CVSS v3

7.5

HIGH

EPSS Score

1.0 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

none

SSVC status

Get an alert for each new CVE published for java.

Set up CVE WatchFree account · no credit card

Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

javaBitnamiall versions · fixed in 1.8.0and 2 other packages
java-1.8.0-openjdkAlmaLinux:9all versions · fixed in 1:1.8.0.482.b08-1.el9.alma.1and 16 other packages
java-1.8.0-openjdkAlmaLinux:8all versions · fixed in 1:1.8.0.482.b08-1.el8and 15 other packages
java-17-openjdkAlmaLinux:9all versions · fixed in 1:17.0.18.0.8-1.el9.alma.1and 22 other packages
java-17-openjdkAlmaLinux:8all versions · fixed in 1:17.0.18.0.8-1.el8and 22 other packages
java-21-openjdkAlmaLinux:10all versions · fixed in 1:21.0.10.0.7-1.el10.alma.1and 22 other packages
java-21-openjdkAlmaLinux:9all versions · fixed in 1:21.0.10.0.7-1.el9.alma.1and 22 other packages
java-21-openjdkAlmaLinux:8all versions · fixed in 1:21.0.10.0.7-1.el8and 22 other packages

2 more package ranges on OSV.dev

Vendor advisories

CVE-2026-21945 Red Hat Product Security3,198 products fixed · 45 known affected
openjdk: Enhance Certificate Checking (Oracle CPU 2026-01)
java-21-ibm-semeru-certified-jdk as a component of Red Hat Enterprise Linux 10 · java-21-ibm-semeru-certified-jdk-devel as a component of Red Hat Enterprise Linux 10 · java-21-ibm-semeru-certified-jdk-headless as a component of Red Hat Enterprise Linux 10
ICSA-26-134-10 CISA1 known affected
Siemens SIMATIC
SIMATIC CN 4100
SSA-032379 Siemens ProductCERT1 known affected
SSA-032379: Multiple Vulnerabilities in SIMATIC CN 4100 Before V5.0
SIMATIC CN 4100
RHSA-2026:4832 Red Hat Product Security22 products fixed
Red Hat Security Advisory: java-1.8.0-ibm security update
RHSA-2026:1606 Red Hat Product Security1 product fixed
Red Hat Security Advisory: OpenJDK 25.0.2 Security Update for Windows Builds
RHSA-2026:0932 Red Hat Product Security780 products fixed
Red Hat Security Advisory: java-1.8.0-openjdk security update

14 more advisories

Full record on NVD

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).

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2026-01-20
Last Modified: 2026-01-30

Frequently asked questions

What is CVE-2026-21945?

Is CVE-2026-21945 actively exploited?

Active exploitation of CVE-2026-21945 has not been confirmed. Its EPSS score was 1.0% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-21945?

CVE-2026-21945 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Running java? Hear about its next vulnerability

CVE Watch matches each new CVE to the vendors and products you list (vendor and product, not the version) and puts it in your alerts with its KEV and EPSS status.

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

Already have an account? Open CVE WatchNo credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? CVE Watch alerts you to new vulnerabilities in your products.

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database