CVE-2026-43198
Medium
Elevated severity or exploit probability.
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2026-05-06 — Published (NVD)
- 2026-09-14 — Last modified (NVD)
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.
Affected
References
- https://git.kernel.org/stable/c/7178e2a8027423b2af17ab95df73a749a5b72e5b
- https://git.kernel.org/stable/c/858d2a4f67ff69e645a43487ef7ea7f28f06deae
- https://git.kernel.org/stable/c/9ed654e340f4c73bc6f0af2fbc90ac293e645ce0
- https://git.kernel.org/stable/c/a7e761ba55efaa9c49e0afdd304bb78167af3429
- https://git.kernel.org/stable/c/aef4a9ae95d1bc4f7897065011e6261026719aeb
- https://git.kernel.org/stable/c/cd644e6dc72eec8d9d988717ea1c54f8668ded69
- https://git.kernel.org/stable/c/dad1fe7db6c6519138430ac8f5e589c18f83bfc9
- https://git.kernel.org/stable/c/fe89b2f05b854847784f91127319172945c1fadd
- 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