CVE-2026-46300: Linux Kernel Missing Initialization of a Variable Vulnerability
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.
- Published by source
- 2026-10-28
- First seen by Reality Radar
- 2026-10-28
- Last verified
- 2026-10-28
Affected
- Manufacturer
- Linux
- Products
- Kernel Linux Kernel
Whether your exact unit is affected depends on the model, serial number and region in the official notice.
What the official notice says
Risk: Actively exploited in the wild
Remedy / actions:
- 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.
Is this affecting you?
Add what you own or use and Reality Radar will tell you when official changes match it — with evidence and next steps.
Sources
- CISA Known Exploited Vulnerabilities Tier A · official published 2026-10-28
Evidence ledger
Every piece of evidence we store is appended to a public hash chain, so later edits are detectable. Anyone can re-verify it.
| Entry | Kind | Observed | Evidence hash | Entry hash |
|---|---|---|---|---|
| #2689 | new | 2026-10-28 | 3c60901cd38b…3aee57 | 5177808ef5d4…74ec1d |
Chain head: #2800 60b0da2762c7…c27b07