CVE-2026-91403

DiscoveredOct 21, 2026UpdatedOct 24, 2026

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…

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CVSS v3.1

9.1 CRITICAL

EPSS

0.31%

probability of exploitation in 30 days

CISA KEV

Not listed

no confirmed exploitation reported

News coverage

sources referencing this CVE

Related IOCs

seen in the same coverage

EPSS Trend

Oct 23, 2026 → Oct 26, 2026

▼ 0.08pp

0.39% → 0.31% over 3 tracked changes

CVSS v3.1 Detail

Attack VectorNETWORK

Attack ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

ScopeUNCHANGED

ConfidentialityHIGH

IntegrityHIGH

AvailabilityNONE

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Connections

3 relationships

Timeline

disclosure → media coverage

Oct 21, 2026

Disclosure — published as a CVE record.

Oct 26, 2026

thehackernews.com reports: ⚡ Weekly Recap: This2Shell, That2Shell, Everything's an RCE? Rogue AI, Supply Chain Chaos and More

Public PoC (4)

github.com/Carl0gonzalez/java-security-update github.com/hubly12/javafix github.com/FahrihFatahilah/CVE-2026-91403-eMudhra-Java-Scanner github.com/siladu/fix-cve-2026-91403

Unverified third-party code — review before executing.