{"cve":"CVE-2026-45889","nvd":{"published":"2026-05-27T14:17:02.927","modified":"2026-06-25T21:11:20.817","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: do not account for OoO in mptcp_rcvbuf_grow()\n\nMPTCP-level OoOs are physiological when multiple subflows are active\nconcurrently and will not cause retransmissions nor are caused by\ndrops.\n\nAccounting for them in mptcp_rcvbuf_grow() causes the rcvbuf slowly\ndrifting towards tcp_rmem[2].\n\nRemove such accounting. Note that subflows will still account for TCP-level\nOoO when the MPTCP-level rcvbuf is propagated.\n\nThis also closes a subtle and very unlikely race condition with rcvspace\ninit; active sockets with user-space holding the msk-level socket lock,\ncould complete such initialization in the receive callback, after that the\nfirst OoO data reaches the rcvbuf and potentially triggering a divide by\nzero Oops.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-369"],"references":["https://git.kernel.org/stable/c/400ee4854adef1e4983812a3decf6717ea020136","https://git.kernel.org/stable/c/6b329393502e5857662b851a13f947209c588587","https://git.kernel.org/stable/c/fb7bf00b04a6b48859f52035d4e745848c2b4c79"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:36:28.938604137+00:00"},"epss":{"cve":"CVE-2026-45889","score":0.00154,"percentile":0.04487,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}