CVE-2026-46300

High

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.

Package Linux Kernel
Published 2026-05-23
Last modified 2026-05-30
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-787

CVE-2026-46300 is a Out-of-bounds Write vulnerability

What is Out-of-bounds Write?

The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 3.9 and later are affected. Fixed in 5.10.257, 5.15.208, 6.1.174, 6.6.141, 6.12.91, 6.18.33, 7.0.10, 7.1-rc5 and their respective stable series.

Affected from
≥ 3.9
Fixed in
✓ 5.10.257 5.10.x ✓ 5.15.208 5.15.x ✓ 6.1.174 6.1.x ✓ 6.6.141 6.6.x ✓ 6.12.91 6.12.x ✓ 6.18.33 6.18.x ✓ 7.0.10 7.0.x ✓ 7.1-rc5

References

The following references provide additional information about CVE-2026-46300 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

8 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2026-46300?

    CVE-2026-46300 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 3.9 onward and has been patched in 5.10.257, 5.15.208, 6.1.174 and others. CVE-2026-46300 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-46300?

    CVE-2026-46300 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-46300?

    Yes — CVE-2026-46300 has been patched. Fixed versions include 5.10.257, 5.15.208, 6.1.174 and others. If you are running Linux kernel 3.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-46300 actively exploited?

    No — CVE-2026-46300 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Out-of-bounds Write (CWE-787)?

    The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →

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