CVE-2026-72243 (GCVE-0-2026-72243)
Vulnerability from cvelistv5
Published
2026-08-15 05:54
Modified
2026-08-18 06:56
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
selinux: check connect-related permissions on TCP Fast Open
Similar to Landlock, SELinux was not updated when TCP Fast Open
support was introduced to ensure connect-related permissions are
checked when using TCP Fast Open. Update its socket_sendmsg() hook to
call selinux_socket_connect() when MSG_FASTOPEN is passed.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: cf60af03ca4e71134206809ea892e49b92a88896 Version: cf60af03ca4e71134206809ea892e49b92a88896 Version: cf60af03ca4e71134206809ea892e49b92a88896 Version: cf60af03ca4e71134206809ea892e49b92a88896 Version: cf60af03ca4e71134206809ea892e49b92a88896 Version: cf60af03ca4e71134206809ea892e49b92a88896 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"security/selinux/hooks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "11406d0d7e11b4e525bb2ace2c70107031d058da",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "e507633bf76bccf1a6af27771fb0d6e2862b7eac",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "fc633a598206d4f23af782db7c0b5f3a82751d2c",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "646ebbc5f2ff9147d084e1213143f091026a611c",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
},
{
"lessThan": "44c74d27d1b9aaa99fa8a83640c1223575262b80",
"status": "affected",
"version": "cf60af03ca4e71134206809ea892e49b92a88896",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"security/selinux/hooks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.6"
},
{
"lessThan": "3.6",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.178",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.145",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.97",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.40",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.5",
"versionStartIncluding": "3.6",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "3.6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nselinux: check connect-related permissions on TCP Fast Open\n\nSimilar to Landlock, SELinux was not updated when TCP Fast Open\nsupport was introduced to ensure connect-related permissions are\nchecked when using TCP Fast Open. Update its socket_sendmsg() hook to\ncall selinux_socket_connect() when MSG_FASTOPEN is passed."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.4,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - Exploitation requires a confined local process to invoke sendmsg(2)/sendto(2) with MSG_FASTOPEN; the vulnerable selinux_socket_sendmsg() LSM hook runs on the syscall path before TCP fast-open performs its implicit connect.\nAC:L - A confined task with SOCKET__WRITE can reliably trigger the bypass with one sendmsg/sendto using MSG_FASTOPEN and a destination address; TFO client is enabled by default (sysctl_tcp_fastopen=TFO_CLIENT_ENABLE) and no race or special victim state is needed.\nPR:L - The attacker must be an unprivileged process in a SELinux domain that grants socket write but denies connect/name_connect (e.g., confined Android apps, container workloads, hardened service domains); no real root or init-namespace privileges are required.\nUI:N - No victim interaction is required; the confined attacker process directly issues the bypassing syscall without needing another user or administrator to perform any action.\nS:C - Successful exploitation crosses the SELinux MAC confinement boundary, allowing a sandboxed domain to establish outbound TCP/MPTCP connections that connect(2) and name_connect policy would have blocked, escaping the intended network policy scope.\nC:H - Bypassing connect and name_connect mediation lets a confined process open TCP/MPTCP sessions to SELinux-forbidden destinations and read arbitrary response data from those services (internal APIs, metadata endpoints, databases), constituting unauthorized information disclosure.\nI:H - The bypass enables unauthorized outbound connection establishment and transmission of arbitrary application data (including SYN-cookie payload) to hosts and ports explicitly denied by SELinux connect/name_connect rules, violating integrity of the confinement policy.\nA:N - This is a pure SELinux LSM policy-bypass flaw with no kernel memory corruption, panic, oops, hang, or resource exhaustion; exploitation does not impact system availability."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-18T06:56:32.099Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/11406d0d7e11b4e525bb2ace2c70107031d058da"
},
{
"url": "https://git.kernel.org/stable/c/e507633bf76bccf1a6af27771fb0d6e2862b7eac"
},
{
"url": "https://git.kernel.org/stable/c/d028bc080a0dcd6a7f8e1ae1bd32dda696505ba3"
},
{
"url": "https://git.kernel.org/stable/c/fc633a598206d4f23af782db7c0b5f3a82751d2c"
},
{
"url": "https://git.kernel.org/stable/c/646ebbc5f2ff9147d084e1213143f091026a611c"
},
{
"url": "https://git.kernel.org/stable/c/44c74d27d1b9aaa99fa8a83640c1223575262b80"
}
],
"title": "selinux: check connect-related permissions on TCP Fast Open",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-72243",
"datePublished": "2026-08-15T05:54:31.117Z",
"dateReserved": "2026-08-09T03:40:39.914Z",
"dateUpdated": "2026-08-18T06:56:32.099Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…