CVE detail
CVE-2026-63828
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 20.8 · diversity 10.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 7
- within the 30d window
- Peak daily
- 6
- highest bucket
Evidence
Source links by recency
7 source links · newest first
Information published.
vendormsrc.microsoft.comJul 20, 2026, 8:07 AMNo excerpt available.
Patchgit.kernel.orgJul 19, 2026, 12:16 PMNo excerpt available.
Patchgit.kernel.orgJul 19, 2026, 12:16 PMNo excerpt available.
Patchgit.kernel.orgJul 19, 2026, 12:16 PMNo excerpt available.
Patchgit.kernel.orgJul 19, 2026, 12:16 PMNo excerpt available.
Patchgit.kernel.orgJul 19, 2026, 12:16 PMNo excerpt available.
Patchgit.kernel.orgJul 19, 2026, 12:16 PM
Exploit code
Public exploit repository references
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