CISA KEV entry
CVE-2026-46300Linux Kernel Missing Initialization of a Variable Vulnerability
Linux Kernel. Added to the CISA Known Exploited Vulnerabilities catalogue on 28 October 2026.
Data status: a source is stale
Last synced CISA catalogue version 2026.11.04 (released 4 November 2026) 1,768 entries Updated manually
- Date added
- 2026-10-28
- Federal due date
- 2026-10-31 3 days after it was added; passed at the sync of 2026-11-05
- Known ransomware use
- Unknown
- Forensic triage (BOD 26-04)
- Yes
- CVSS
- 7.8 High CVSS 3.1, scored by nvd@nist.gov
- EPSS
- 16.13% percentile 96.9, scored 2026-11-04
- CISA SSVC
- Exploitation active, automatable no, technical impact total
- NVD status
- Analyzed published 2026-05-23, 158 days before the KEV listing
BOD 26-04 remediation window
With CISA's SSVC answers for this CVE (automatable: no, technical impact: total), BOD 26-04 Table 1 gives 3 days and forensic triage on a publicly exposed asset (row 3) and 14 days on an asset that is not publicly exposed (row 11) S06. CISA set the catalogue due date at 3 days; under BOD 26-04 it reflects CISA's own view of whether the flaw sits on publicly exposed assets S07. The directive binds US federal civilian executive branch agencies only.
What CISA says
Short description
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.
Required action
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.
Notes
This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: ; https://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987 ; https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c ; https://git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5 ; https://git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0 ; https://git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e ; https://git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a ; https://git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111 ; https://git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-46300
CWE in the catalogue
CWE-456
Official links
- CISA KEV catalogue entry cisa.gov
- NVD record nvd.nist.gov
Vendor advisory and patch links
References NVD tags Vendor Advisory or Patch, exactly as NVD lists them.
- https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c Patch
- https://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987 Patch
- https://git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111 Patch
- https://git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a Patch
- https://git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e Patch
- https://git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0 Patch
- https://git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5 Patch
- https://git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3 Patch
Links in CISA's notes
- https://git.kernel.org/stable/c/3599e6b3cc1ada96883d496a50a210d3afbb6987
- https://git.kernel.org/stable/c/2f2b16022a2e10ca7bccfb98db5ed2ec0f72641c
- https://git.kernel.org/stable/c/9d3e5fd19fe1063bf607219e8562fbd567b8e8d5
- https://git.kernel.org/stable/c/78bf6b6bb19541d19fbda6242e7cfe2c682763c0
- https://git.kernel.org/stable/c/760e1addc27ba1a7beb4a0a7e8b3e9ec49e7a34e
- https://git.kernel.org/stable/c/3bd9e113d50034db99d7ef69fd8e5242d15e414a
- https://git.kernel.org/stable/c/3884358a9286b17f389a72b1426fc4547c23c111
- https://git.kernel.org/stable/c/f84eca5817390257cef78013d0112481c503b4a3
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2026-46300
NVD details
- CWE (NVD)
- CWE-787 by nvd@nist.gov, CWE-456 by CISA ADP, CWE-123 by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- CVSS versions in NVD
- V31
- Last modified in NVD
- 2026-10-29T17:30:34.060
Where each value comes from
| Field | Source | Fetched, UTC | State |
|---|---|---|---|
| Catalogue fields | CISA KEV JSON, version 2026.11.04 | 2026-11-05 11:38 | current |
| NVD published, status, CVSS, CWE, vendor links | NVD CVE API 2.0; CVSS: NVD (nvd@nist.gov) | 2026-11-03 12:37 | current at 2026-11-05 11:38 |
| EPSS | FIRST EPSS API, scores of 2026-11-04 | 2026-11-05 11:38 | current |
| CISA SSVC | CISA ADP (via NVD), record of 2026-05-14 | 2026-11-03 12:37 | current |
This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.