mptcp: allow subflow rcv wnd to shrink
In the Linux kernel, the following vulnerability has been resolved: mptcp: allow subflow rcv wnd to shrink In MPTCP connection, the `window` field in the TCP header refers to the MPTCP-level rcv_nxt and it's right edge should not move backward. Such constraint is enforced at DSS option generation time. At the same time, the TCP stack ensures independently that the TCP-level rcv wnd right's edge does not move backward. That in turn causes artificial inflating of the MPTCP rcv window when the incoming data is acked at the TCP level and is OoO in the MPTCP sequence space (or lands in the backlog). As a consequence, the incoming traffic can exceed the receiver rcvbuf size even when the sender is not misbehaving. Prevent such scenario forcibly allowing the TCP subflow to shrink the TCP-level rcv wnd regardless of the current netns setting.
CVE-2026-53183
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-53183
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "f3589be0c420a3137e5902d15705ced6a36f3f43",
"lessThan": "bf364b0f10b27679140699821f88af7f01e2a6e3",
"versionType": "git"
},
{
"status": "affected",
"version": "f3589be0c420a3137e5902d15705ced6a36f3f43",
"lessThan": "b1fd13074f22105deec45aa02283e322733e0c2d",
"versionType": "git"
},
{
"status": "affected",
"version": "f3589be0c420a3137e5902d15705ced6a36f3f43",
"lessThan": "aa3861f40ac32706d9e97bfac76984613e278788",
"versionType": "git"
},
{
"status": "affected",
"version": "f3589be0c420a3137e5902d15705ced6a36f3f43",
"lessThan": "653245266913f03fcf21cbca68eed5c197a33e52",
"versionType": "git"
},
{
"status": "affected",
"version": "f3589be0c420a3137e5902d15705ced6a36f3f43",
"lessThan": "c297a4e65c50a2b807d9309b22615080faffa8f3",
"versionType": "git"
},
{
"status": "affected",
"version": "f3589be0c420a3137e5902d15705ced6a36f3f43",
"lessThan": "da23be77e1292cd611e736c3aa17da633d7ddce7",
"versionType": "git"
}
],
"programFiles": [
"net/mptcp/options.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.94",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.36",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.13",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/mptcp/options.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-53183
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40765 · Revision 1
- Added to Heist Feed
- Publisher date