Security readout for executives and security teams
Plain-English summary
CVE-2026-21928 is an Oracle Solaris 11 kernel vulnerability that can expose some readable data to an unauthenticated attacker over TCP. It is not described as enabling system takeover, data modification, or outage. Business urgency is highest for Solaris systems reachable from untrusted networks.
Executive priority
Treat as a moderate-priority confidentiality risk. Patch in the normal security update cycle, faster for externally reachable Solaris 11 systems or systems handling sensitive data.
Technical view
Oracle reports an easily exploitable Oracle Solaris Kernel flaw affecting supported Solaris 11. The CVSS 3.1 vector is AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N, scored 5.3. The mapped weakness is CWE-200, exposure of sensitive information to an unauthorized actor.
Likely exposure
Exposure depends on Oracle Solaris 11 hosts with network-accessible TCP services or kernel attack surface reachable by unauthenticated users. Internet-facing, partner-facing, or broadly reachable internal Solaris systems should be prioritized for review.
Exploitation context
The provided sources do not state active exploitation, and the CVE is not marked as CISA KEV. Oracle characterizes the issue as remotely reachable over TCP, low complexity, and requiring no credentials or user interaction.
Researcher notes
Public details are limited to Oracle's advisory-level description and CVSS vector. No affected subcomponent beyond Kernel, proof of concept, or specific data type exposed is provided in the source bundle.
Mitigation direction
- Review Oracle's January 2026 Critical Patch Update guidance for Solaris 11.
- Apply the vendor-recommended Solaris updates when approved for your environment.
- Restrict network access to Solaris hosts from untrusted networks where feasible.
- Prioritize remediation for internet-facing or sensitive-data Solaris systems.
Validation and detection
- Inventory all Oracle Solaris 11 systems in production and support environments.
- Confirm whether each system is covered by Oracle's January 2026 CPU guidance.
- Check patch or package baselines against Oracle's advisory instructions.
- Review network exposure for unauthenticated TCP access to Solaris hosts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-21928 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- Oracle AdvisoryCVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.