{"id":"CVE-2026-89969","title":"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 …","summary":"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 …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < a3f0bcfbaf3312a5754d1ce020a07d394669eb25","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < 4f84d42c53c49557fb1ef285c683b0a81b576c74","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < 58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < 3a385e0c39efbe34db8edd95900c123113ae3450","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < d95d342bc0ea82dc79e6362b2f1f997431750e4c","Linux >= 872d26a391da92ed8f0c0f5cb5fef428067b7f30 < 14cc5a7e77731497d5bea70f3bb05df7eda982e4","Linux 5.0"],"published":"2026-09-16","updated":"2026-09-16","sourceUpdated":"2026-09-16T15:18:21.240","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89969","references":[{"url":"https://git.kernel.org/stable/c/14cc5a7e77731497d5bea70f3bb05df7eda982e4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3a385e0c39efbe34db8edd95900c123113ae3450","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4f84d42c53c49557fb1ef285c683b0a81b576c74","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/58dc6035b79c4c73c0cbf9ec9f68a7f117b2b3e6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a3f0bcfbaf3312a5754d1ce020a07d394669eb25","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cf5f39d2b58f97e0cd1829c4a6aeef17f1607cca","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d95d342bc0ea82dc79e6362b2f1f997431750e4c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dbc4acbdb3ca8c81441368ad7409b8f77d4de8f6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-16T10:53:53.956Z","epss":0.00695,"epssPercentile":0.51126,"slug":"CVE-2026-89969","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":205075,"id":"CVE-2026-89969","ts":1789570705097,"field":"cvss","old":null,"new":"9.8"},{"seq":205074,"id":"CVE-2026-89969","ts":1789570705097,"field":"severity","old":"none","new":"critical"}]}