USN-8667-1: Linux kernel (KVM) vulnerabilities

unknownpublic exploitCVE-2020-24588 CVE-2025-27558 CVE-2021-47378 CVE-2026-23392 CVE-2026-31402 CVE-2026-31405

Siebe Devroe, Héloïse Gollier, and Mathy Vanhoef discovered that the WiFi implementation in the Linux kernel did not properly handle aggregated frames in mesh networks, due to an incorrect fix for CVE-2020-24588. A physically proximate attacker could use this issue to inject packets. (CVE-2025-27558) 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: - x86 architecture; - Cryptographic API; - InfiniBand drivers; - Media drivers; - NVIDIA Tegra memory controller driver; - Network drivers; - NVME drivers; - File systems infrastructure; - Ext4 file system; - Network file system (NFS) server daemon; - IPv4 networking; - Network traffic control; - TCP network protocol; - Tracing infrastructure; - Locking primitives; - B.A.T.M.A.N. meshing protocol; - Ceph Core library; - IPv6 networking; - Multipath TCP; - Netfilter; - RxRPC session sockets; - SCTP protocol; - SMC sockets; - TIPC protocol; (CVE-2021-47378, CVE-2026-23392, CVE-2026-31402, CVE-2026-31405, CVE-2026-31414, CVE-2026-31448, CVE-2026-31657, CVE-2026-31668, CVE-2026-43037, CVE-2026-43071, CVE-2026-43198, CVE-2026-43493, CVE-2026-43499, CVE-2026-45988, CVE-2026-46119, CVE-2026-46135, CVE-2026-46266, CVE-2026-46331, CVE-2026-52914, CVE-2026-52924, CVE-2026-52931, CVE-2026-52955, CVE-2026-52958, CVE-2026-52982, CVE-2026-52986, CVE-2026-52989, CVE-2026-52993, CVE-2026-52999, CVE-2026-53002, CVE-2026-53006, CVE-2026-53045, CVE-2026-53088, CVE-2026-53176, CVE-2026-53212, CVE-2026-53228, CVE-2026-53359)

CSIRTS triage

vendor: Linux product: Linux kernel Denial of service Memory corruption Code injection

What: Multiple kernel security flaws across x86, cryptographic, InfiniBand, media, networking, and file system subsystems; WiFi mesh network frame aggregation issue enabling packet injection.
Who is affected: Systems running affected Linux kernel versions; physically proximate attackers can exploit WiFi mesh implementation.
Urgency: Multiple issues with varying severity; kernel patch should be applied as part of maintenance.
Action: Apply kernel security updates provided by distribution maintainer.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Ubuntu Security Notices (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-08-21
Exploitation: Not in CISA KEV at last sync

Original advisory: https://ubuntu.com/security/notices/USN-8667-1

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.

Moderate exploitation riskCVE-2020-245883.5% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 88% of all EPSS-scored CVEs.
Low exploitation riskCVE-2025-275580.29% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all EPSS-scored CVEs.
Moderate exploitation riskCVE-2021-473781.2% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 64% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-233920.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-314020.49% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 40% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-314050.55% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 44% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-314140.40% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-314480.44% 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-2026-316570.40% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 33% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-316680.44% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 37% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2020-24588	coverage & exploitation status	NVD · CVE.org
CVE-2025-27558	coverage & exploitation status	NVD · CVE.org
CVE-2021-47378	coverage & exploitation status	NVD · CVE.org
CVE-2026-23392	coverage & exploitation status	NVD · CVE.org
CVE-2026-31402	coverage & exploitation status	NVD · CVE.org
CVE-2026-31405	coverage & exploitation status	NVD · CVE.org
CVE-2026-31414	coverage & exploitation status	NVD · CVE.org
CVE-2026-31448	coverage & exploitation status	NVD · CVE.org
CVE-2026-31657	coverage & exploitation status	NVD · CVE.org
CVE-2026-31668	coverage & exploitation status	NVD · CVE.org
CVE-2026-43037	coverage & exploitation status	NVD · CVE.org
CVE-2026-43071	coverage & exploitation status	NVD · CVE.org
CVE-2026-43198	coverage & exploitation status	NVD · CVE.org
CVE-2026-43493	coverage & exploitation status	NVD · CVE.org
CVE-2026-43499	coverage & exploitation status	NVD · CVE.org
CVE-2026-45988	coverage & exploitation status	NVD · CVE.org
CVE-2026-46119	coverage & exploitation status	NVD · CVE.org
CVE-2026-46135	coverage & exploitation status	NVD · CVE.org
CVE-2026-46266	coverage & exploitation status	NVD · CVE.org
CVE-2026-46331	coverage & exploitation status	NVD · CVE.org
CVE-2026-52914	coverage & exploitation status	NVD · CVE.org
CVE-2026-52924	coverage & exploitation status	NVD · CVE.org
CVE-2026-52931	coverage & exploitation status	NVD · CVE.org
CVE-2026-52955	coverage & exploitation status	NVD · CVE.org
CVE-2026-52958	coverage & exploitation status	NVD · CVE.org
CVE-2026-52982	coverage & exploitation status	NVD · CVE.org
CVE-2026-52986	coverage & exploitation status	NVD · CVE.org
CVE-2026-52989	coverage & exploitation status	NVD · CVE.org
CVE-2026-52993	coverage & exploitation status	NVD · CVE.org
CVE-2026-52999	coverage & exploitation status	NVD · CVE.org
CVE-2026-53002	coverage & exploitation status	NVD · CVE.org
CVE-2026-53006	coverage & exploitation status	NVD · CVE.org
CVE-2026-53045	coverage & exploitation status	NVD · CVE.org
CVE-2026-53088	coverage & exploitation status	NVD · CVE.org
CVE-2026-53176	coverage & exploitation status	NVD · CVE.org
CVE-2026-53212	coverage & exploitation status	NVD · CVE.org
CVE-2026-53228	coverage & exploitation status	NVD · CVE.org
CVE-2026-53359	coverage & exploitation status	NVD · CVE.org

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