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Vulnerabilities

Vulnerability · CVE-2026-63830

In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterl…

Published Jul 19, 2026 · catalog updated Oct 22, 2026 · linux kernel

Check if you run it

No confirmed exploitation is on record for CVE-2026-63830. EPSS is 0.35%. Act only if a listed version of linux kernel is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical9.4
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.35%
Remediation
Version ranges on file
Affected products
cpe linux/linux kernel

In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writable BPF ctx->data. This protects entries backed by pages that are not private to the sk_msg, such as splice-backed file page-cache pages. Several sk_msg transform paths move, copy, split, or compact msg->sg.data[] entries without moving the matching sg.copy bit. This can make an externally backed entry arrive at a new slot with a clear copy bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable ctx->data and BPF stores can modify the original page cache. Keep sg.copy synchronized with sg.data[] whenever entries are transferred, shifted, split, or copied into a new sk_msg. Clear the bit when an entry is replaced by a newly allocated private page or freed. This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(), sk_msg_xfer(), and tls_split_open_record(), including the partial tail entry created during TLS open-record splitting.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernel< 5.10.261
  • cpe linux/linux kernel< 5.15.212
  • cpe linux/linux kernel< 6.1.177
  • cpe linux/linux kernel< 6.12.95
  • cpe linux/linux kernel< 6.18.38
  • cpe linux/linux kernel< 6.6.144
  • cpe linux/linux kernel< 7.1.3

How to fix CVE-2026-63830

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-63830. EPSS is 0.35%. Act only if a listed version of linux kernel is installed.

Which versions are affected?

Compare what you have installed with linux/linux kernel < 5.10.261; linux/linux kernel < 5.15.212; linux/linux kernel < 6.1.177; linux/linux kernel < 6.12.95. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-269: Improper Privilege Management; CWE-863: Incorrect Authorization. EPSS 0.35%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 19, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writable BPF ctx->data. This protects entries backed by pages that are not private to the sk_msg, such as splice-backed file pa

  2. Oct 22, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writable BPF ctx->data. This protects entries backed by pages that are not private to the sk_msg, such as splice-backed file pa

Sources

  • CVE.orgVulnerability recordCVE-2026-63830

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-63830

    30-day exploitation probability 0.35%

    first.org
  • NIST NVDVulnerability recordCVE-2026-63830

    In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writa

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 23, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

CVE-2026-63830: In the Linux kernel, the following vulnerability ha… · ZeroDay Findings