CVE-2026-43198
In 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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In 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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.30% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-362, CWE-821
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5bPatch
- https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deaePatch
- https://git.kernel.org/stable/c/fe89b2f05b854847784f91127319172945c1faddPatch
- https://access.redhat.com/errata/RHSA-2026:30129
- https://access.redhat.com/errata/RHSA-2026:33215
- https://access.redhat.com/errata/RHSA-2026:33285
- https://access.redhat.com/errata/RHSA-2026:34094
- https://access.redhat.com/errata/RHSA-2026:34443
- https://access.redhat.com/errata/RHSA-2026:35863
- https://access.redhat.com/errata/RHSA-2026:35894
- https://access.redhat.com/errata/RHSA-2026:35896
- https://access.redhat.com/errata/RHSA-2026:35904
- https://access.redhat.com/errata/RHSA-2026:36073
- https://access.redhat.com/errata/RHSA-2026:36216
- https://access.redhat.com/errata/RHSA-2026:36348
- https://access.redhat.com/errata/RHSA-2026:36349
- https://access.redhat.com/errata/RHSA-2026:41236
- https://access.redhat.com/security/cve/CVE-2026-43198
- https://bugzilla.redhat.com/show_bug.cgi?id=2467228
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43198.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.