Red Hat Security Advisory: OpenJDK 17.0.21 Security Update for Windows Builds
Affects Red Hat OpenJDK 17.0.21Source GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 5.9 Medium · fixed in Red Hat package updates : update Red Hat java-se when convenient.
Data as of 29 Oct 2026, 17:23 UTC
Thin evidence
One scorer or none| CNA (oracle) | CVSS 3.1 | 5.9 |
|---|
- Patch
- Available – fixed in 17.0.21
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 20 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Oracle CorporationOracle Java SE | Affected
| Fixed in– |
| Oracle CorporationOracle GraalVM for JDK | Affected
| Fixed in– |
| Oracle CorporationOracle GraalVM Enterprise Edition | Affected
| Fixed in– |
Mavencom.oracle.java/java-sepkg:maven/com.oracle.java/java-seOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users of the Red Hat build of OpenJDK 17 on Windows should update to version 17.0.21, which includes fixes for all listed vulnerabilities. Before applying this update, ensure that all previously released errata relevant to your system have been applied. Refer to Red Hat's official update instructions at https://access.redhat.com/articles/11258 for detailed guidance on applying this security update.
Description
Red Hat has released a security update for its OpenJDK 17 build for Windows (version 17.0.21) that addresses multiple security vulnerabilities. This update replaces versions 17.0.20 and 17.0.20.1 and includes numerous enhancements and fixes related to cryptographic padding, TLS certificate handling, LDAP logins, SASL authentication, HTTP client and server handling, XML processing, image handling, Kerberos validation, and distrust of certain intermediate CA certificates. The update is rated critical by Red Hat Product Security.
References
- access.redhat.com/errata/RHSA-2026:89916 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- docs.redhat.com/en/documentation/red_hat_build_of_openjdk/17/html/release_notes_for_red_hat_build_of_openjdk_17.0.21/index (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2556709 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2556795 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2556824 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2556837 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2556859 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557007 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557032 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557041 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557047 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557079 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557110 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557117 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557122 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557195 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557236 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557261 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2557356 (opens in a new tab)