tcp: fix potential race in tcp_v6_syn_recv_sock()

Summary

CVECVE-2026-43198
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-06 12:16:38 UTC
Updated2026-07-20 12:19:22 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: tcp: fix potential race in tcp_v6_syn_recv_sock() Code in tcp_v6_syn_recv_sock() after the call to tcp_v4_syn_recv_sock() is done too late. After tcp_v4_syn_recv_sock(), the child socket is already visible from TCP ehash table and other cpus might use it. Since newinet->pinet6 is still pointing to the listener ipv6_pinfo bad things can happen as syzbot found. Move the problematic code in tcp_v6_mapped_child_init() and call this new helper from tcp_v4_syn_recv_sock() before the ehash insertion. This allows the removal of one tcp_sync_mss(), since tcp_v4_syn_recv_sock() will call it with the correct context.

Risk And Classification

Primary CVSS: v3.1 7 HIGH from ADP

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

EPSS: 0.000480000 probability, percentile 0.148790000 (date 2026-05-12)

Problem Types: CWE-362 | CWE-821 | CWE-821 Incorrect Synchronization


VersionSourceTypeScoreSeverityVector
3.1ADPCVSS7HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary7HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 fe89b2f05b854847784f91127319172945c1fadd git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 7178e2a8027423b2af17ab95df73a749a5b72e5b git Not specified
CNA Linux Linux affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 858d2a4f67ff69e645a43487ef7ea7f28f06deae git Not specified
CNA Linux Linux affected 2.6.12 Not specified
CNA Linux Linux unaffected 2.6.12 semver Not specified
CNA Linux Linux unaffected 6.18.16 6.18.* semver Not specified
CNA Linux Linux unaffected 6.19.6 6.19.* semver Not specified
CNA Linux Linux unaffected 7.0 * original_commit_for_fix Not specified
ADP Red Hat Red Hat Enterprise Linux 10 unaffected 0:6.12.0-211.28.1.el10_2 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support unaffected 0:6.12.0-55.84.1.el10_0 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support unaffected 0:3.10.0-1160.155.1.rt56.1307.el7 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support unaffected 0:3.10.0-1160.155.1.el7 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8 unaffected 0:4.18.0-553.140.1.rt7.481.el8_10 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8 unaffected 0:4.18.0-553.140.1.el8_10 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support unaffected 0:4.18.0-305.197.1.el8_4 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On unaffected 0:4.18.0-305.197.1.el8_4 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support unaffected 0:4.18.0-372.199.1.el8_6 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On unaffected 0:4.18.0-372.199.1.el8_6 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service unaffected 0:4.18.0-477.150.1.el8_8 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions unaffected 0:4.18.0-477.150.1.el8_8 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 9 unaffected 0:5.14.0-687.20.1.el9_8 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions unaffected 0:5.14.0-284.179.1.el9_2 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions unaffected 0:5.14.0-284.179.1.rt14.464.el9_2 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions unaffected 0:5.14.0-427.135.1.el9_4 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support unaffected 0:5.14.0-570.125.1.el9_6 * rpm Not specified
ADP Red Hat Red Hat Enterprise Linux 6 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux 9 Not specified Not specified

References

ReferenceSourceLinkTags
access.redhat.com/security/cve/CVE-2026-43198 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:35904 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:36349 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:35894 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:35896 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:36073 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
access.redhat.com/errata/RHSA-2026:35863 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
access.redhat.com/errata/RHSA-2026:34443 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:30129 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:33215 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:41236 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com
access.redhat.com/errata/RHSA-2026:36216 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
git.kernel.org/stable/c/fe89b2f05b854847784f91127319172945c1fadd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
access.redhat.com/errata/RHSA-2026:34094 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:33285 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43198.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
access.redhat.com/errata/RHSA-2026:36348 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
ADP2026-05-06T00:00:00.000ZReported to Red Hat.
ADP2026-05-06T00:00:00.000ZMade public.

Solutions

ADP: RHSA-2026:36216: Red Hat Enterprise Linux Server (v. 7 ELS), Red Hat Enterprise Linux Server Optional (v. 7 ELS)

ADP: RHSA-2026:41236: Red Hat Enterprise Linux for Real Time (v. 7 ELS)

ADP: RHSA-2026:33215: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux BaseOS EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0), Red Hat Enterprise Linux Real Time EUS (v. 10.0), Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)

ADP: RHSA-2026:30129: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10)

ADP: RHSA-2026:36073: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux BaseOS E4S (v.9.2)

ADP: RHSA-2026:34443: Red Hat Enterprise Linux AppStream E4S (v.9.4), Red Hat Enterprise Linux BaseOS E4S (v.9.4), Red Hat Enterprise Linux Real Time E4S (v.9.4), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)

ADP: RHSA-2026:34094: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6), Red Hat Enterprise Linux Real Time EUS (v.9.6), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6)

ADP: RHSA-2026:33285: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9)

ADP: RHSA-2026:36349: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8)

ADP: RHSA-2026:35896: Red Hat Enterprise Linux BaseOS AUS (v.8.4), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)

ADP: RHSA-2026:35894: Red Hat Enterprise Linux BaseOS AUS (v.8.6), Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)

ADP: RHSA-2026:35863: Red Hat Enterprise Linux BaseOS E4S (v.8.8), Red Hat Enterprise Linux BaseOS TUS (v.8.8)

ADP: RHSA-2026:36348: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8)

ADP: RHSA-2026:35904: Red Hat Enterprise Linux Real Time E4S (v.9.2), Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)

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