USN-8658-4: Linux kernel (Azure CVM) vulnerabilities
Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - Open vSwitch; - SCTP protocol; (CVE-2026-53224, CVE-2026-53246, CVE-2026-64531)
CSIRTS triage
- What
- Linux kernel Azure CVM variant contains vulnerabilities in Open vSwitch and SCTP protocol subsystems.
- Who is affected
- Azure Confidential Virtual Machines running affected Linux kernel versions.
- Urgency
- Medium; limited scope to vSwitch and SCTP components warrants standard patching timeline.
- Action
- Update to USN-8658-4 or later kernel version for Azure CVM deployments.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://ubuntu.com/security/notices/USN-8658-4
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-532240.52% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-532460.44% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-645310.38% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 31% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-53224 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53246 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-64531 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownUSN-8661-4: Linux kernel vulnerabilitiesubuntu
- unknownUSN-8715-1: Linux kernel (Oracle) vulnerabilitiesubuntu
- unknownUSN-8714-1: Linux kernel vulnerabilitiesubuntu
- unknownSUSE Linux Kernel Multiple Vulnerabilitieshkcert
- unknownMultiple vulnerabilities in SUSE Linux kernel (August 28, 2026)cert-fr-avis
- unknownUSN-8644-3: Linux kernel (Azure) vulnerabilitiesubuntu
- unknownUSN-8661-3: Linux kernel vulnerabilitiesubuntu
- unknownUSN-8643-5: Linux kernel vulnerabilitiesubuntu
- unknownUSN-8659-4: Linux kernel (Oracle) vulnerabilityubuntu
- unknownUSN-8658-3: Linux kernel vulnerabilitiesubuntu
- unknownUSN-8643-4: Linux kernel vulnerabilitiesubuntu
- unknownUSN-8659-3: Linux kernel (Azure) vulnerabilityubuntu
More from Ubuntu Security Notices
- unknownUSN-8717-1: Apache Tika vulnerability2026-09-03
- unknownUSN-8661-4: Linux kernel vulnerabilities2026-09-02
- unknownUSN-8715-1: Linux kernel (Oracle) vulnerabilities2026-09-02
- unknownUSN-8714-1: Linux kernel vulnerabilities2026-09-02
- unknownUSN-8713-1: BioSig vulnerabilities2026-09-02