{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80588","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-26T14:34:25.770Z","datePublished":"2026-08-26T14:37:42.685Z","dateUpdated":"2026-08-27T05:02:09.335Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-27T05:02:09.335Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: reclaim forward-allocated memory on RX path errors\n\nAfter commit 9db5b3cec4ec (\"mptcp: borrow forward memory from subflow\"),\nerrors in the receive path prior to queueing skbs into the receive\nqueue do not trigger forward-allocated memory reclaiming.\n\nPrevent forward memory from growing unboundedly in pathological drop\nscenarios by explicitly reclaiming memory when skbs are dropped."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - Remote TCP/MPTCP peers reach the bug on the established-connection RX datapath (tcp_rcv_established → subflow_data_ready → mptcp_data_ready → __mptcp_move_skbs_from_subflow → __mptcp_move_skb → mptcp_drop) when duplicate or out-of-window mapped data is dropped before skb_set_owner_r().\nAC:L - The attacker fully controls subflow packet contents and ordering on their MPTCP connection and can deterministically trigger drops (duplicate map_seq, OoO beyond rcv_wnd) on every crafted segment without races, rare sysctl state, or uncontrollable memory layout.\nPR:N - No local account or kernel capability is required on the victim; any remote peer that completes the TCP/MPTCP handshake on an IPPROTO_MPTCP socket (Android clients, MPTCP-enabled servers, curl --mptcp) can flood pathological RX drops without target credentials.\nUI:N - Exploitation needs only attacker-generated MPTCP/TCP traffic on an existing or attacker-initiated connection; no victim mount, file open, click, or other cooperative user action beyond normal network stack processing.\nS:U - Impact is unbounded sk_forward_alloc growth and kernel memory exhaustion on the affected host; it does not cross VM, container, IOMMU, or sandbox boundaries to another security authority.\nC:N - This is a forward-memory accounting leak on skb drop after mptcp_borrow_fwdmem(); skb data is freed and no use-after-free, out-of-bounds read, or other memory-corruption primitive exposes kernel contents to the attacker.\nI:N - The flaw only fails to reclaim borrowed forward allocation when dropping skbs; it does not corrupt, overwrite, or modify attacker-chosen memory and provides no write or code-execution primitive.\nA:H - Each pre-queue drop leaks roughly skb->truesize forward memory while bypassing the removed sk_rmem_schedule guard, so a remote peer can repeatedly trigger unbounded per-connection kernel memory growth and OOM denial of service, matching CNA precedent for repeatable network skb/memory leaks."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"],"versions":[{"version":"a84164847b1e0a106ebc46821e5d2f9b775c9dc8","lessThan":"473f1a5ab2abc98dd9e74b95b9c23c66c47535cc","status":"affected","versionType":"git"},{"version":"9db5b3cec4ec1c0cd3239689f5c8653d691a1754","lessThan":"8277f48a06d3aa1441f6d0b6998ccc0360d30ed8","status":"affected","versionType":"git"},{"version":"9db5b3cec4ec1c0cd3239689f5c8653d691a1754","lessThan":"41b49a8b914ec7dcb03eae93fb27f3c464078644","status":"affected","versionType":"git"},{"version":"6.18.35","lessThan":"6.18.46","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"],"versions":[{"version":"6.19","status":"affected"},{"version":"0","lessThan":"6.19","status":"unaffected","versionType":"semver"},{"version":"6.18.46","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.10","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.35","versionEndExcluding":"6.18.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.1.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/473f1a5ab2abc98dd9e74b95b9c23c66c47535cc"},{"url":"https://git.kernel.org/stable/c/8277f48a06d3aa1441f6d0b6998ccc0360d30ed8"},{"url":"https://git.kernel.org/stable/c/41b49a8b914ec7dcb03eae93fb27f3c464078644"}],"title":"mptcp: reclaim forward-allocated memory on RX path errors","x_generator":{"engine":"bippy-1.2.0"}}}}