# CVE-2026-63828: apparmor: mediate the implicit connect of TCP fast open sendmsg CVE-2026-63828 is fixed in 35 products on 1 platform, first by ALAS2023-2026-1969, released July 20, 2026. It is not reported as exploited. Patch Radar priority: Urgent. - Web page: https://patchblox.com/security/cve/CVE-2026-63828 - Priority: Urgent - CVSS: 9.8 (Critical) - EPSS: 0.0017 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 19, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63828 ## Description In the Linux kernel, the following vulnerability has been resolved: apparmor: mediate the implicit connect of TCP fast open sendmsg sendmsg()/sendto() with MSG_FASTOPEN is a combination of connect(2) and write(2): it opens the connection in the SYN. apparmor_socket_sendmsg() only checks AA_MAY_SEND, so a profile that grants send but denies connect lets a confined task open an outbound TCP/MPTCP connection that connect(2) would have refused, bypassing connect mediation. Mediate the implicit connect when MSG_FASTOPEN is set and a destination is supplied. Add it to apparmor_socket_sendmsg() (not the shared aa_sock_msg_perm() helper, which recvmsg also uses) and call aa_sk_perm() directly, mirroring the selinux and tomoyo fixes. sk_is_tcp() does not cover MPTCP fast open, so the SOCK_STREAM/IPPROTO_MPTCP arm is explicit. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.38.1.160000.2.22 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.81.1.150700.17.45.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.38.1.160000.2.23 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-livepatch-6.18.38-73.137 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_20 sles 15.7 | 1-150700.1.3.1 | [SUSE-SU-2026:4120-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4120-1.md) | Sep 10, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_21 sles 15.7 | 1-150700.15.3.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.38.1 | [OPENSUSE-SU-2026:21910-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21910-1.md) | Sep 22, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.81.1 | [SUSE-SU-2026:4254-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4254-1.md) | Oct 7, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.38.1 | [SUSE-SU-2026:23902-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23902-1.md) | Sep 22, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | linux Debian 12.15 (bookworm) | 6.1.177-1 | [DEBIAN-CVE-2026-63828](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63828.md) | Jul 20, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.95-1 | [DEBIAN-CVE-2026-63828](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63828.md) | Jul 20, 2026 | | Linux | linux Debian 14 | 7.1.3-1 | [DEBIAN-CVE-2026-63828](https://patchblox.com/security/data/fix/linux/debian-cve-2026-63828.md) | Jul 20, 2026 | | Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.38-73.137.amzn2023 | [ALAS2023-2026-1969](https://patchblox.com/security/data/fix/linux/alas2023-2026-1969.md) | Jul 20, 2026 | --- Data as of 2026-11-10T01:44:33Z UTC. 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