Linux kernel: skb sharedfrag flag mispropagated in fragtransfer helpers
CVE-2026-46300 Published on May 23, 2026

net: skbuff: preserve shared-frag marker during coalescing
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.

NVD

Vulnerability Analysis

CVE-2026-46300 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Write-what-where Condition

Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.


Products Associated with CVE-2026-46300

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-46300 are published in these products:

Amazon Aws
 
Linux Kernel
 
Canonical Ubuntu Linux
 
Red Hat Enterprise Linux Nvidia
 
Red Hat Openshift
 
Red Hat Enterprise Linux Eus
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Rhel E4s
 
Red Hat Rhel Eus
 
Red Hat Rhel Aus
 
Red Hat Rhel Eus Long Life
 
Red Hat Rhel Tus
 

Affected Versions

Linux: Linux: Red Hat NVIDIA for RHEL 10: Red Hat OpenShift Container Platform 4.21: Red Hat OpenShift Container Platform 4.12: Red Hat OpenShift Container Platform 4.13: Red Hat OpenShift Container Platform 4.14: Red Hat OpenShift Container Platform 4.15: Red Hat OpenShift Container Platform 4.16: Red Hat OpenShift Container Platform 4.17: Red Hat OpenShift Container Platform 4.18: Red Hat OpenShift Container Platform 4.19: Red Hat OpenShift Container Platform 4.20: Red Hat Enterprise Linux AppStream EUS (v. 10.0): Red Hat Enterprise Linux AppStream (v. 10): Red Hat Enterprise Linux AppStream E4S (v.9.0): Red Hat Enterprise Linux AppStream E4S (v.9.2): Red Hat Enterprise Linux AppStream EUS (v.9.4): Red Hat Enterprise Linux AppStream EUS (v.9.6): Red Hat Enterprise Linux AppStream (v. 9): Red Hat Enterprise Linux BaseOS EUS (v. 10.0): Red Hat Enterprise Linux BaseOS (v. 10): Red Hat Enterprise Linux BaseOS (v. 8): Red Hat Enterprise Linux BaseOS AUS (v.8.4): Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4): Red Hat Enterprise Linux BaseOS AUS (v.8.6): Red Hat Enterprise Linux BaseOS E4S (v.8.6): Red Hat Enterprise Linux BaseOS TUS (v.8.6): Red Hat Enterprise Linux BaseOS E4S (v.8.8): Red Hat Enterprise Linux BaseOS TUS (v.8.8): Red Hat Enterprise Linux BaseOS E4S (v.9.0): Red Hat Enterprise Linux BaseOS E4S (v.9.2): Red Hat Enterprise Linux BaseOS E4S (v.9.4): Red Hat Enterprise Linux BaseOS EUS (v.9.4): Red Hat Enterprise Linux BaseOS EUS (v.9.6): Red Hat Enterprise Linux BaseOS (v. 9): Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0): Red Hat Enterprise Linux CodeReady Linux Builder (v. 10): Red Hat Enterprise Linux CRB (v. 8): Red Hat CodeReady Linux Builder EUS (v.9.4): Red Hat CodeReady Linux Builder EUS (v.9.6): Red Hat Enterprise Linux CodeReady Linux Builder (v. 9): Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0): Red Hat Enterprise Linux Real Time for NFV (v. 10): Red Hat Enterprise Linux NFV (v. 8): Red Hat Enterprise Linux NFV E4S (v.9.0): Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2): Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4): Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6): Red Hat Enterprise Linux Real Time for NFV (v. 9): Red Hat Enterprise Linux Real Time EUS (v. 10.0): Red Hat Enterprise Linux Real Time (v. 10): Red Hat Enterprise Linux RT (v. 8): Red Hat Enterprise Linux Real Time E4S (v.9.0): Red Hat Enterprise Linux Real Time E4S (v.9.2): Red Hat Enterprise Linux Real Time EUS (v.9.4): Red Hat Enterprise Linux Real Time EUS (v.9.6): Red Hat Enterprise Linux Real Time (v. 9): Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7:

Exploit Probability

EPSS
1.58%
Percentile
72.36%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.