{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89969", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.778Z", "datePublished": "2026-09-16T10:32:49.603Z", "dateUpdated": "2026-10-19T08:55:42.820Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:55:42.820Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet-tcp: fix out-of-bounds write when receiving an over-long PDU\n\nnvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte\nqueue->pdu union, then computes the remaining payload length as\n\n\tqueue->left = hdr->hlen - queue->offset + hdgst;\n\nand reads that many more bytes into &queue->pdu + queue->offset, without\never bounding the result against sizeof(queue->pdu).\n\nA struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the\nunion. Once a header digest has been negotiated (hdgst = 4), a second\nICReq passes the hlen == nvmet_tcp_pdu_size() check but yields\nqueue->left = 128 - 8 + 4 = 124, so bytes 8..132 are written into the\n128-byte buffer -- 4 bytes past its end, over queue->hdr_digest and\nqueue->data_digest. Those bytes are attacker-controlled (an ICReq\ncarries no digest), and the duplicate ICReq is only rejected later,\nafter the overflow. A remote unauthenticated host can thus corrupt\nkernel memory adjacent to the receive buffer.\n\nReject any PDU whose declared length would read past the end of\nqueue->pdu before the second recv." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is in nvmet-tcp, an in-kernel NVMe-over-TCP target that accepts remote TCP connections; nvmet_tcp_try_recv_pdu() copies attacker-controlled PDU bytes from the socket, so the overflow is reachable from any network peer that can connect to an exposed NVMe-oF TCP port (typical cloud/storage-server deployment).\nAC:L - The attacker enables header digest in the first ICReq (the target copies the initiator's digest flags with no extra configuration), then sends a second 128-byte ICReq; queue->left becomes 124 and four attacker-controlled bytes are written past queue->pdu with no race or condition outside attacker control.\nPR:N - The overflow fires on a duplicate ICReq after TCP accept and digest negotiation, before NVMe Connect, host NQN allow-list, or DH-HMAC-CHAP in-band authentication; no Linux credentials or capabilities on the target are required.\nUI:N - Exploitation requires only attacker-sent NVMe/TCP PDUs to an already listening target port; no victim user action such as mounting a filesystem or opening a device is needed.\nS:U - The out-of-bounds write corrupts fields of the host's nvmet_tcp_queue in kernel memory and does not cross a VM, hypervisor, container, or IOMMU security boundary.\nC:H - Attacker-controlled 4-byte overflow into kernel memory adjacent to queue->pdu is memory corruption that, per kernel guidance, can be leveraged for information disclosure (including by clearing hdr_digest so later verify_hdgst is skipped and by controlling the persisted digest-flag bytes).\nI:H - This is an attacker-controlled out-of-bounds write past the 128-byte queue->pdu union into adjacent kernel fields (hdr_digest and data_digest); per kernel guidance an OOB write is High integrity impact and can disable PDU digest verification before the duplicate ICReq is rejected.\nA:H - After the overflow, nvmet_tcp_done_recv_pdu() returns -EPROTO and nvmet_tcp_socket_error() calls nvmet_ctrl_fatal_error() once a controller exists (e.g. after unauthenticated Discovery Connect), taking down the NVMe target; the kernel memory corruption can also oops, and the trigger is remotely repeatable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/tcp.c" ], "versions": [ { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "a3f0bcfbaf3312a5754d1ce020a07d394669eb25", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "4f84d42c53c49557fb1ef285c683b0a81b576c74", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "3a385e0c39efbe34db8edd95900c123113ae3450", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "d95d342bc0ea82dc79e6362b2f1f997431750e4c", "status": "affected", "versionType": "git" }, { "version": "872d26a391da92ed8f0c0f5cb5fef428067b7f30", "lessThan": "14cc5a7e77731497d5bea70f3bb05df7eda982e4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/nvme/target/tcp.c" ], "versions": [ { "version": "5.0", "status": "affected" }, { "version": "0", "lessThan": "5.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.0", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.0", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a3f0bcfbaf3312a5754d1ce020a07d394669eb25" }, { "url": "https://git.kernel.org/stable/c/4f84d42c53c49557fb1ef285c683b0a81b576c74" }, { "url": "https://git.kernel.org/stable/c/58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6" }, { "url": "https://git.kernel.org/stable/c/cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca" }, { "url": "https://git.kernel.org/stable/c/3a385e0c39efbe34db8edd95900c123113ae3450" }, { "url": "https://git.kernel.org/stable/c/dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6" }, { "url": "https://git.kernel.org/stable/c/d95d342bc0ea82dc79e6362b2f1f997431750e4c" }, { "url": "https://git.kernel.org/stable/c/14cc5a7e77731497d5bea70f3bb05df7eda982e4" } ], "title": "nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU", "x_generator": { "engine": "bippy-1.2.0" } } } }