CVE-2026-45889

linux: In the Linux kernel, the following vulnerability has been resolved: mptcp: do not account for OoO in mptcp_rcvbuf_gr...

CVE-2026-45889 is fixed in 23 products on 1 platform, first by ALAS2023-2026-1514, released March 30, 2026. It is not reported as exploited. Patch Radar priority: Routine.

Routine
CVSS
5.5
medium
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0015
4th percentile

In the Linux kernel, the following vulnerability has been resolved: mptcp: do not account for OoO in mptcp_rcvbuf_grow() MPTCP-level OoOs are physiological when multiple subflows are active concurrently and will not cause retransmissions nor are caused by drops. Accounting for them in mptcp_rcvbuf_grow() causes the rcvbuf slowly drifting towards tcp_rmem[2]. Remove such accounting. Note that subflows will still account for TCP-level OoO when the MPTCP-level rcvbuf is propagated. This also closes a subtle and very unlikely race condition with rcvspace init; active sockets with user-space holding the msk-level socket lock, could complete such initialization in the receive callback, after that the first OoO data reaches the rcvbuf and potentially triggering a divide by zero Oops.

Where it's fixed

ProductFixed inFixReleased
Linux
bpftool6.18 · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
bpftool6.18-debuginfo · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel-livepatch-6.18.15-14.217 · amzn 2023 1:1.0-0.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18 · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-debuginfo · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-debuginfo-common-aarch64 · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-debuginfo-common-x86_64 · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-devel · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-headers · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-libbpf · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-libbpf-debuginfo · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-libbpf-devel · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-libbpf-static · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-modules-extra · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-modules-extra-common · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-tools · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-tools-debuginfo · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
kernel6.18-tools-devel · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
linux · Debian 14 6.18.14-1 DEBIAN-CVE-2026-45889 May 27, 2026
perf6.18 · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
perf6.18-debuginfo · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
python3-perf6.18 · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026
python3-perf6.18-debuginfo · amzn 2023 1:6.18.15-14.217.amzn2023 ALAS2023-2026-1514 Mar 30, 2026

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