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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-63828 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
https://git.kernel.org/stable/c/07b71c342382b854ab8030b244aeab6a7228ad7d kernel.org
https://git.kernel.org/stable/c/45ebb934ea50b436ce49b2f159f090dab0d7fa28 kernel.org
https://git.kernel.org/stable/c/4a69b83045d3195d5b9a9b053ad840ddb2998b4e kernel.org
https://git.kernel.org/stable/c/4d587cd8a72155089a627130bbd4716ec0856e21 kernel.org
https://git.kernel.org/stable/c/7f57428ce00891d26b0f087ef754a4d820ec83aa kernel.org
https://git.kernel.org/stable/c/faea60deaa05c76f0772650f42eafde12bd39d93 kernel.org

Weakness Enumeration

CWE-ID CWE Name Source

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-63828
NVD Published Date:
07/19/2026
NVD Last Modified:
07/20/2026
Source:
kernel.org