{"id":"CVE-2026-53191","revision":"f766b40073694622908a624017f11e2f","records":[{"revision":"f766b40073694622908a624017f11e2f","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53191","aliases":[],"title":"io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries\n\nWhen a bundle recv retries inside io_recv_finish(), the merge logic OR\nthe saved cflags from the previous iteration with the cflags returned by\nthe new iteration:\n  cflags = req->cqe.flags | (cflags & CQE_F_MASK);\n\nBits listed in CQE_F_MASK are inherited from the new iteration, and all\nother bits (notably IORING_CQE_F_BUFFER and the buffer ID) come from the\nsaved cflags. Before this change CQE_F_MASK covered only\nIORING_CQE_F_SOCK_NONEMPTY and IORING_CQE_F_MORE.\n\nWhen using provided buffer rings (IOU_PBUF_RING_INC) with incremental\nmode, and bundle recv, io_kbuf_inc_commit() can leave the head ring\nentry partially consumed, __io_put_kbufs() then sets\nIORING_CQE_F_BUF_MORE on the returned cflags so userspace knows the\nbuffer ID will be reused for subsequent completions.\n\nBecause IORING_CQE_F_BUF_MORE was not in CQE_F_MASK, the merge above\nsilently dropped it whenever the final retry iteration partially\nconsumed the buffer, and the subsequent req->cqe.flags = cflags &\n~CQE_F_MASK save would have left a stale IORING_CQE_F_BUF_MORE in the\ncarried-over cflags had one been present. Userspace would then\nwrongfully advance it ring head past an entry the kernel still uses.\n\nAdd IORING_CQE_F_BUF_MORE to CQE_F_MASK so it is both inherited from the\nnew iteration into the user-visible CQE and stripped from the saved\ncflags between iterations.","state":0,"publishedAt":"2026-06-25T08:39:03.052+00:00","modifiedAt":"2026-10-19T19:57:27.637+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"io_uring/net.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"ae98dbf43d755b4e111fcd086e53939bef3e9a1a\",\n                            \"lessThan\": \"f40570fda3f3a1f96aeaa4aef665ba274b2810b5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ae98dbf43d755b4e111fcd086e53939bef3e9a1a\",\n                            \"lessThan\": \"0bbc9481f970b0b4ddb08cfa464db1cc93b74b56\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ae98dbf43d755b4e111fcd086e53939bef3e9a1a\",\n                            \"lessThan\": \"4973232a67e4137ab9399f504f7f2bdd847f96d2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ae98dbf43d755b4e111fcd086e53939bef3e9a1a\",\n                            \"lessThan\": \"ed46f39c47eb5530a9c161481a2080d3a869cfaf\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"io_uring/net.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.12\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.94\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.36\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.13\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/f40570fda3f3a1f96aeaa4aef665ba274b2810b5","https://git.kernel.org/stable/c/0bbc9481f970b0b4ddb08cfa464db1cc93b74b56","https://git.kernel.org/stable/c/4973232a67e4137ab9399f504f7f2bdd847f96d2","https://git.kernel.org/stable/c/ed46f39c47eb5530a9c161481a2080d3a869cfaf"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53191","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53191","identifiers":["CVE-2026-53191"]},"retained":false,"historicalAffected":[]}],"coverage":[]}