Answer in brief
CVE-2026-53183 records a High severity (CVSS 7.5) vulnerability in mptcp: allow subflow rcv wnd to shrink. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f3589be0c420a3137e5902d15705ced6a36f3f43 <bf364b0f10b27679140699821f88af7f01e2a6e3 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <b1fd13074f22105deec45aa02283e322733e0c2d || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <aa3861f40ac32706d9e97bfac76984613e278788 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <653245266913f03fcf21cbca68eed5c197a33e52 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <c297a4e65c50a2b807d9309b22615080faffa8f3 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <da23be77e1292cd611e736c3aa17da633d7ddce7 | bf364b0f10b27679140699821f88af7f01e2a6e3, b1fd13074f22105deec45aa02283e322733e0c2d, aa3861f40ac32706d9e97bfac76984613e278788, 653245266913f03fcf21cbca68eed5c197a33e52, c297a4e65c50a2b807d9309b22615080faffa8f3, da23be77e1292cd611e736c3aa17da633d7ddce7 |
| Linux/Linuxgeneric | 5.19 | Not reported |
Published upstream
Jun 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 25, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-53183 records a High severity (CVSS 7.5) vulnerability in mptcp: allow subflow rcv wnd to shrink. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=f3589be0c420a3137e5902d15705ced6a36f3f43 <bf364b0f10b27679140699821f88af7f01e2a6e3 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <b1fd13074f22105deec45aa02283e322733e0c2d || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <aa3861f40ac32706d9e97bfac76984613e278788 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <653245266913f03fcf21cbca68eed5c197a33e52 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <c297a4e65c50a2b807d9309b22615080faffa8f3 || >=f3589be0c420a3137e5902d15705ced6a36f3f43 <da23be77e1292cd611e736c3aa17da633d7ddce7 | bf364b0f10b27679140699821f88af7f01e2a6e3, b1fd13074f22105deec45aa02283e322733e0c2d, aa3861f40ac32706d9e97bfac76984613e278788, 653245266913f03fcf21cbca68eed5c197a33e52, c297a4e65c50a2b807d9309b22615080faffa8f3, da23be77e1292cd611e736c3aa17da633d7ddce7 |
| Linux/Linuxgeneric | 5.19 | Not reported |
Published upstream
Jun 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 25, 2026
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.
Quoted source text, attributed separately from HOL analysis.