CVE-2026-63828

highpriority · track · 10EPSS 0.002 · 6 %ileexploit · PoCDEEUFRRU
grimoire priorityP1 · Urgent
Exploitable?
Public exploit
1 exploit · PoC
Likely / severe?
0.17% (6th) EPSS
CVSS 8.4 · high
Is it mine?
53 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-26

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

8.4
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.18.4highAV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Nsecondary · FSTEC (BDU) RU
v3.18.4highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Nsecondary · ENISA EU
v3.18.4highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Nsecondaryexploitability 2 · impact 5.8
v3.17.9highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N/E:Psecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-1220US
03

exploits (1)

Public proof-of-concept and weaponised exploit code.

04

affected products (53)

Products and version ranges known to be affected.

showing 20 of 53
05

advisories (3)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-2403Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2026-07-19csaf · cert_bundDE

    Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, möglicherweise Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen oder vertrauliche Informationen offenzulegen.

  • CERTFR-2026-AVI-1333Multiples vulnérabilités dans le noyau Linux d'UbuntuFrançais2026-10-16vendor · certfrFR
  • CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdfstec_bducert_bundcertfrNVDCVE.orgMITRE
published 2026-07-19modified 2026-10-08
08

references (23)

External citations — patches, advisories, analysis.

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