CVE-2026-72243
SELinux connect-permission bypass via TCP Fast Open in Linux kernel.
Is CVE-2026-72243 being exploited?
Not confirmed. CVE-2026-72243 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.16% probability of exploitation in the next 30 days.
How severe is CVE-2026-72243?
CVE-2026-72243 is rated High. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-72243?
Yes. A fix has been recorded for CVE-2026-72243. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-72243 affect?
CVE-2026-72243 affects Linux kernel with SELinux and TCP Fast Open enabled, Major distros (RHEL/Fedora, Ubuntu/Debian, SUSE). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-72243?
Install vendor kernel updates or backport patch; disable TCP Fast Open if urgent.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Confined local processes can bypass SELinux connect checks using MSG_FASTOPEN, enabling unauthorized outbound connections, exfiltration or lateral movement.
Patch when possible
- affected>= cf60af03ca4e71134206809ea892e49b92a88896 and < 11406d0d7e11b4e525bb2ace2c70107031d058da
- affected>= cf60af03ca4e71134206809ea892e49b92a88896 and < e507633bf76bccf1a6af27771fb0d6e2862b7eac
- affected>= cf60af03ca4e71134206809ea892e49b92a88896 and < d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3
- affected>= cf60af03ca4e71134206809ea892e49b92a88896 and < fc633a598206d4f23af782db7c0b5f3a82751d2c
- affected>= cf60af03ca4e71134206809ea892e49b92a88896 and < 646ebbc5f2ff9147d084e1213143f091026a611c
- affected>= cf60af03ca4e71134206809ea892e49b92a88896 and < 44c74d27d1b9aaa99fa8a83640c1223575262b80
- affected3.6
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.