CVE-2026-46300Linux Kernel Missing Initialization of a Variable Vulnerability
- Product
- Linux Kernel
- Added to CISA KEV
- October 28, 2026
- Deadline for US federal agencies
- October 31, 2026
- Known ransomware use
- Not known
- EPSS, next 30 days
- 16%, higher than 96% of scored CVEs (Nov 7, 2026)
- Weakness
- CWE-456
What CISA says
Linux Kernel contains a missing initialization of a variable vulnerability that could allow for unintended modification of page-cache-backed data via failure to preserve the shared-fragment marker during socket buffer coalescing, causing ESP input processing to decrypt shared fragments in place. This vulnerability can be chained with CVE-2026-109618 and CVE-2026-109619 to implant PHP webshells and run commands as root.
What CISA asks you to do
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Sources
- git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987
- git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c
- git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5
- git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0
- git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e
- git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a
- git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111
- git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3
- NVD entry: nvd.nist.gov/vuln/detail/CVE-2026-46300
- CISA KEV catalog
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Data from CISA's Known Exploited Vulnerabilities catalog (public domain) and FIRST EPSS, refreshed hourly. Rheono did not find or test this vulnerability; this page summarizes public sources.