How severe is CVE-2026-91537?

CVE-2026-91537 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-91537?

Affected package information for CVE-2026-91537 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-91537?

No fixed release is recorded for CVE-2026-91537 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2026-91537 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-91537 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2026-91537 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-91537 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-91537?

CVE-2026-91537 has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 2th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2026-91537 published, and has it been updated?

CVE-2026-91537 was published on October 20, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

Not in CISA KEV

HIGH severity

CVE-2026-91537 — Oracle

HIGH

CVE-2026-91537 is a high-severity (CVSS 7.8) vulnerability. No vendor fix is recorded yet; mitigation options are listed below.

Vulnerability in the Oracle Solaris product of Oracle Systems (component: Utility). The supported version that is affected is 11.4. Easily exploitable vulnerability allows low privileged…

Published

Oct 20, 2026

Updated

Oct 21, 2026

Affected

—

Patched

—

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs2th percentile — riskier than 2% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-91537 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,415 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

Vulnerability in the Oracle Solaris product of Oracle Systems (component: Utility). The supported version that is affected is 11.4. Easily exploitable vulnerability allows low privileged attacker with logon to the infrastructure where Oracle Solaris executes to compromise Oracle Solaris. Successful attacks of this vulnerability can result in takeover of Oracle Solaris. CVSS 3.1 Base Score 7.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2026-91537 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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