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CVE-2026-46300

7.8, high Known exploited

Linux Kernel Missing Initialization of a Variable Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab) CISA KEV catalogue (opens in a new tab)
CVSS
7.8, high high CVSS v3.1
EPSS, next 30 days
10% higher than 95.6% of scored CVEs
Exploitation
Confirmed in the wild
Published
23 May 20265 months ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 28 Oct 2026. US federal agencies must remediate by 31 Oct 2026.

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.

Description

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned or page-cache-backed frags, but the shared-frag marker is currently lost. That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags. Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors.

Details

Vendor
Linux and 2 more
Product
Linux
Weakness
CWE-787 (opens in a new tab)
Status
Undergoing analysis
Updated
28 Oct 2026
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References 51

Patches and fixes 8

Advisories 6

Other references 37

29 more

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Linux CVEs

Every Linux CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-53362 Linux Kernel Unspecified Vulnerability KEV EPSS 0.7% 7.8, high
  • CVE-2026-53266 Linux Kernel Out-of-Bounds Write Vulnerability KEV EPSS 0.9% 8.8, high
  • CVE-2026-31431 Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability KEV EPSS 98% 7.8, high
  • CVE-2025-39964 Linux Kernel Race Condition Vulnerability KEV EPSS 2% 5.5, medium
  • CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability KEV EPSS 3% 9.8, critical
  • CVE-2025-38352 Linux Kernel Time-of-Check Time-of-Use (TOCTOU) Race Condition Vulnerability KEV EPSS 1% 7.8, high
  • CVE-2024-53197 Linux Kernel Out-of-Bounds Access Vulnerability KEV EPSS 4% 7.8, high
  • CVE-2024-53150 Linux Kernel Out-of-Bounds Read Vulnerability KEV EPSS 1% 7.1, high

Beyond this page

Is CVE-2026-46300 in your network?

This page tells you how dangerous CVE-2026-46300 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2026-46300 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2026-46300 comes with the devices to patch.

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 29 Oct 2026, not the live upstream state.