USN-8644-1: Linux kernel 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: - File systems infrastructure; - OCFS2 file system; - B.A.T.M.A.N. meshing protocol; - SCTP protocol; - TIPC protocol; (CVE-2026-43071, CVE-2026-52914, CVE-2026-52993, CVE-2026-53043, CVE-2026-53224, CVE-2026-53246, CVE-2026-53309)
CSIRTS triage
- What
- Multiple security flaws in Linux kernel subsystems including file systems infrastructure, OCFS2, B.A.T.M.A.N., SCTP, and TIPC protocols.
- Who is affected
- Linux systems running affected kernel versions.
- Urgency
- Medium; multiple kernel vulnerabilities require timely updates to prevent system compromise.
- Action
- Apply the latest kernel security updates via your Linux distribution's patch mechanism.
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-8644-1
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-2026-430710.39% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 32% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-529140.51% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 41% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-529930.37% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 29% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-530430.73% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 52% of all EPSS-scored CVEs.
- 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-2026-533090.76% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 52% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-43071 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-52914 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-52993 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53043 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53224 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53246 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53309 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownUSN-8666-2: Linux kernel (Azure) vulnerabilitiesubuntu
- unknownUSN-8630-5: Linux kernel (Raspberry Pi) vulnerabilitiesubuntu
- unknownUSN-8658-3: Linux kernel vulnerabilitiesubuntu
- unknownUSN-8643-4: Linux kernel vulnerabilitiesubuntu
- high[UPDATE] [high] Linux Kernel: Multiple vulnerabilitiescert-bund
- medium[UPDATE] [medium] Linux Kernel: Multiple Vulnerabilitiescert-bund
- medium[UPDATE] [medium] Linux Kernel: Multiple vulnerabilitiescert-bund
- high[UPDATE] [high] Linux Kernel: Multiple vulnerabilitiescert-bund
- unknownUSN-8658-2: Linux kernel (IBM) vulnerabilitiesubuntu
- lowUSN-8661-2: Linux kernel (Low Latency) vulnerabilitiesubuntu
- unknownUSN-8643-3: Linux kernel (NVIDIA) vulnerabilitiesubuntu
- unknownUSN-8668-1: Linux kernel (GCP) vulnerabilitiesubuntu
More from Ubuntu Security Notices
- unknownUSN-8659-4: Linux kernel (Oracle) vulnerability2026-08-26
- unknownUSN-8666-2: Linux kernel (Azure) vulnerabilities2026-08-25
- unknownUSN-8630-5: Linux kernel (Raspberry Pi) vulnerabilities2026-08-25
- unknownUSN-8658-3: Linux kernel vulnerabilities2026-08-25
- unknownUSN-8643-4: Linux kernel vulnerabilities2026-08-25