CVE-2026-63926 - Vulnerability Details

- bpf: sockmap: fix tail fragment offset in bpf_msg_push_data

Description

In the Linux kernel, the following vulnerability has been resolved:

bpf: sockmap: fix tail fragment offset in bpf_msg_push_data

When bpf_msg_push_data() inserts data in the middle of a scatterlist
entry, it splits the original entry into a left fragment and a right
fragment.

The right fragment offset is page-local, but the code advances it with
`start`, which is the message-global insertion point. For inserts into a
non-first SG entry, this over-advances the offset and leaves the split
layout inconsistent.

Advance the right fragment offset by the fragment-local delta,
`start - offset`, which matches the length removed from the front of the
original entry.

Published: 2026-07-19

Score: 8.4 High

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< f14609d8146707452e0822f3c8154674ce677251
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< d81b323af2dcee47573907ccb89c0df9b45cb2e2
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< aeb95146848d12206e1b2cfacd4f40e21ce81d94
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< 96b72672ce849a1402730238e64d9b20bf06a96d
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< 3075c21d2d76c0067f4a382765b43d6cc10470f1
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< 5e19028667963fb371ebb00cecc2a473ef92056b
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< 63f64a510c7917658ddf4d073ece73914ee25346
`6fff607e2f14bd7c63c06c464a6f93b8efbabe28`	affected	< f72eed9b84fb771019a955908132410a9ba9ea3f

Linux

affected

Version	Status	Constraints
`4.20`	affected	—
`0`	unaffected	< 4.20
`5.10.259`	unaffected	≤ 5.10.*
`5.15.210`	unaffected	≤ 5.15.*
`6.1.176`	unaffected	≤ 6.1.*
`6.6.143`	unaffected	≤ 6.6.*
`6.12.93`	unaffected	≤ 6.12.*
`6.18.35`	unaffected	≤ 6.18.*
`7.0.12`	unaffected	≤ 7.0.*
`7.1`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[6fff607e2f14bd7c63c06c464a6f93b8efbabe28,f14609d8146707452e0822f3c8154674ce677251)`	affected	code_commit	—
`[6fff607e2f14bd7c63c06c464a6f93b8efbabe28,d81b323af2dcee47573907ccb89c0df9b45cb2e2)`	affected	code_commit	—
`[6fff607e2f14bd7c63c06c464a6f93b8efbabe28,aeb95146848d12206e1b2cfacd4f40e21ce81d94)`	affected	code_commit	—
`[6fff607e2f14bd7c63c06c464a6f93b8efbabe28,96b72672ce849a1402730238e64d9b20bf06a96d)`	affected	code_commit	—
`[6fff607e2f14bd7c63c06c464a6f93b8efbabe28,3075c21d2d76c0067f4a382765b43d6cc10470f1)`	affected	code_commit	—
`[6fff607e2f14bd7c06c464a6f93b8efbabe28,5e19028667963fb371ebb00cecc2a473ef92056b)`	affected	code_commit	—
`[6fff607e2f14bd7c06c464a6f93b8efbabe28,63f64a510c7917658ddf4d073ece73914ee25346)`	affected	code_commit	—
`[6fff607e2f14bd7c06c464a6f93b8efbabe28,f72eed9b84fb771019a955908132410a9ba9ea3f)`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`4.20`	affected	generic	—
`[0,4.20)`	unaffected	generic	—
`[5.10.259,5.11.0)`	unaffected	semver	—
`[5.15.210,5.16.0)`	unaffected	semver	—
`[6.1.176,6.2.0)`	unaffected	semver	—
`[6.6.143,6.7.0)`	unaffected	semver	—
`[6.12.93,6.13.0)`	unaffected	semver	—
`[6.18.35,6.19.0)`	unaffected	semver	—
`[7.0.12,7.1.0)`	unaffected	semver	—
`[7.1,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
Ubuntu USN	USN-8593-1	Linux kernel vulnerabilities
Ubuntu USN	USN-8603-1	Linux kernel (Azure) vulnerabilities

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.0018.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/3075c21d2d76c0067f4a382765b43d6cc10470f1
https://git.kernel.org/stable/c/5e19028667963fb371ebb00cecc2a473ef92056b
https://git.kernel.org/stable/c/63f64a510c7917658ddf4d073ece73914ee25346
https://git.kernel.org/stable/c/96b72672ce849a1402730238e64d9b20bf06a96d
https://git.kernel.org/stable/c/aeb95146848d12206e1b2cfacd4f40e21ce81d94
https://git.kernel.org/stable/c/d81b323af2dcee47573907ccb89c0df9b45cb2e2
https://git.kernel.org/stable/c/f14609d8146707452e0822f3c8154674ce677251
https://git.kernel.org/stable/c/f72eed9b84fb771019a955908132410a9ba9ea3f
https://lore.kernel.org/linux-cve-announce/2026071949-CVE-2026-63926-cc75@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-63926
https://www.cve.org/CVERecord?id=CVE-2026-63926

History

Wed, 22 Jul 2026 00:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-823
References		https://lore.kernel.org/linux-cve-announce/2026071949-CVE-2026-63926-cc75@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-63926 https://www.cve.org/CVERecord?id=CVE-2026-63926
Metrics	threat_severity `None`	threat_severity `Moderate`

Mon, 20 Jul 2026 14:45:00 +0000

Type	Values Removed	Values Added
Metrics		cvssV3_1 `{'score': 8.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}`

Sun, 19 Jul 2026 15:30:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: bpf: sockmap: fix tail fragment offset in bpf_msg_push_data When bpf_msg_push_data() inserts data in the middle of a scatterlist entry, it splits the original entry into a left fragment and a right fragment. The right fragment offset is page-local, but the code advances it with `start`, which is the message-global insertion point. For inserts into a non-first SG entry, this over-advances the offset and leaves the split layout inconsistent. Advance the right fragment offset by the fragment-local delta, `start - offset`, which matches the length removed from the front of the original entry.
Title		bpf: sockmap: fix tail fragment offset in bpf_msg_push_data
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/3075c21d2d76c0067f4a382765b43d6cc10470f1 https://git.kernel.org/stable/c/5e19028667963fb371ebb00cecc2a473ef92056b https://git.kernel.org/stable/c/63f64a510c7917658ddf4d073ece73914ee25346 https://git.kernel.org/stable/c/96b72672ce849a1402730238e64d9b20bf06a96d https://git.kernel.org/stable/c/aeb95146848d12206e1b2cfacd4f40e21ce81d94 https://git.kernel.org/stable/c/d81b323af2dcee47573907ccb89c0df9b45cb2e2 https://git.kernel.org/stable/c/f14609d8146707452e0822f3c8154674ce677251 https://git.kernel.org/stable/c/f72eed9b84fb771019a955908132410a9ba9ea3f

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-07-19T14:55:27.154Z

Updated: 2026-07-20T13:41:36.086Z

Reserved: 2026-07-19T07:54:57.021Z

Link: CVE-2026-63926

Vulnrichment

No data.

NVD

No data.

Redhat

Severity : Moderate

Publid Date: 2026-07-19T00:00:00Z

Links: CVE-2026-63926 - Bugzilla

OpenCVE Enrichment

Updated: 2026-07-24T05:30:05Z

Weaknesses

CWE-823

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

Subscriptions

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