How do I check whether I am affected by CVE-2026-91462?

- Run `java -version` and compare the reported build with the affected versions listed in the sources: `8u503`, `11.0.32.1`, `17.0.20.1`, `21.0.12.1`, `25.0.4.1`, and GraalVM `21.3.19.1.1`. - Check whether the application's web services pass untrusted data into JGSS-backed APIs (Kerberos/GSS-API use).

What is the fix for CVE-2026-91462?

- Upgrade Oracle Java SE to a patched release from Oracle's Critical Patch Update for this CVE; the sources list the affected builds but do not name the fixed version. - Upgrade Oracle GraalVM for JDK and GraalVM Enterprise to a patched build from Oracle.

Who is not affected by CVE-2026-91462?

Not affected if: not-listed-versions.

Live › vulnerability › CVE-2026-91462

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medium5.9Runtime

Oracle Java SE: JGSS flaw lets remote attacker alter data

A flaw in the JGSS component of Oracle Java SE and GraalVM lets an unauthenticated attacker with network access change or delete data by supplying crafted input to Java APIs, such as through a web service. The attack is hard to carry out, and the CVSS score is 5.9 with an integrity-only impact.

Summary written from the sources below. Check the originals before acting.

CVSS 3.x

5.9

medium

scored by [email protected]

known so far3 of 6

missing: versions, primary source, exploitation

First public: Oct 20, 2026 UTC
Last modified: Oct 21, 2026
Status: open
Known exploitation: None reported
Public exploit: None on GitHub
EPSS: not scored

First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.

Why it is medium, and not just CVSS

Likelihood → · Impact ↓

critical

high

medium

high

medium

low

medium

low

Exploited: No reports yet.
Needs login: No.
Needs a special setup: Not known from the sources.
Reachable from: internet.
Worst case: Attacker can alter or delete data the Java application can access.
CVSS said: 5.9. The facts above say high; we keep the sources' medium until an analyst looks.

Who is affected

Teams running Oracle Java SE 8, 11, 17, 21, or 25 builds listed above, or Oracle GraalVM for JDK or Enterprise builds, especially services that accept network input and call JGSS APIs. Systems that do not run these builds can skip it. The sources do not say which JGSS APIs are most exposed.

Know the next one before it finds you.

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Live › vulnerability › CVE-2026-91462

Go to dashboard

medium5.9Runtime

Oracle Java SE: JGSS flaw lets remote attacker alter data

Summary written from the sources below. Check the originals before acting.

CVSS 3.x

5.9

medium

scored by [email protected]

known so far3 of 6

missing: versions, primary source, exploitation

First public: Oct 20, 2026 UTC
Last modified: Oct 21, 2026
Status: open
Known exploitation: None reported
Public exploit: None on GitHub
EPSS: not scored

First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.

Why it is medium, and not just CVSS

Likelihood → · Impact ↓

critical

high

medium

high

medium

low

medium

low

Exploited: No reports yet.
Needs login: No.
Needs a special setup: Not known from the sources.
Reachable from: internet.
Worst case: Attacker can alter or delete data the Java application can access.
CVSS said: 5.9. The facts above say high; we keep the sources' medium until an analyst looks.

Who is affected

Know the next one before it finds you.

Add to Slack

Oracle Java SE: JGSS flaw lets remote attacker alter data

Why it is medium, and not just CVSS

Who is affected

Know the next one before it finds you.

Oracle Java SE: JGSS flaw lets remote attacker alter data

Why it is medium, and not just CVSS

Who is affected

Know the next one before it finds you.

How to check

The fix

Who had it, and when

What the sources say, verbatim

Sources