{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-17523",
        "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "state": "PUBLISHED",
        "assignerShortName": "redhat",
        "dateReserved": "2026-07-27T08:19:11.242Z",
        "datePublished": "2026-07-27T08:58:58.143Z",
        "dateUpdated": "2026-09-10T13:31:17.266Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-09-10T13:31:17.266Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: bcm: switch timer to HRTIMER_MODE_SOFT and remove hrtimer_tasklet\n\nThis patch switches the timer to HRTIMER_MODE_SOFT, which executed the\ntimer callback in softirq context and removes the hrtimer_tasklet."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - The UAF is in bcm_remove_op() hrtimer/tasklet teardown, reached only via local PF_CAN/CAN_BCM syscalls (socket/connect/sendmsg TX_SETUP or RX_SETUP with STARTTIMER, then close or TX_DELETE/RX_DELETE). Remote IP services or CAN bus frames alone cannot close the socket or delete the op.\nAC:L - The attacker controls both sides of the race: they arm cyclic TX/RX hrtimers with attacker-chosen microsecond intervals, then delete the op or close the socket, hitting the TOCTOU between tasklet-state checks and hrtimer_active() in bcm_remove_op(). The window is retryable until the scheduled tasklet runs on the freed object.\nPR:L - can_create(), bcm_connect(), and bcm_sendmsg() have no capability checks. RX_SETUP with ifindex 0 starts timeout timers without a CAN device, so any unprivileged local user (including via user namespaces / vcan) can create BCM ops and trigger teardown.\nUI:N - Exploitation requires only the attacker opening a BCM socket, installing timer-armed TX_SETUP/RX_SETUP ops, and closing or deleting them; no victim action such as mounting a filesystem or opening a file is needed.\nS:U - The use-after-free corrupts kernel heap state in the same kernel security domain, enabling local privilege escalation or crash; it does not by itself cross a VM, guest-to-host, or IOMMU boundary.\nC:H - bcm_op is a kmalloc object that embeds tasklet_struct; after the hrtimer hardirq callback schedules a tasklet that bcm_remove_op() misses, the tasklet runs on freed memory. Heap reuse of tsklet.func/data and UAF reads in bcm_send_to_user()/bcm_can_tx() enable arbitrary kernel disclosure.\nI:H - The same UAF lets a sprayed tasklet_struct hijack tsklet.func for arbitrary kernel execution, and bcm_tx_timeout_tsklet()/bcm_can_tx() write through freed op fields (frames, sock, timers), providing arbitrary write and control-flow hijack primitives.\nA:H - A scheduled tasklet running after kfree(op) dereferences the freed bcm_op (and its frames/sk pointers), causing kernel oops/panic even when the UAF is not fully turned into code execution."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/can/bcm.c"
                    ],
                    "versions": [
                        {
                            "version": "c53a6ee88b0a91bd012ef1b7988c0b93dae6f24d",
                            "lessThan": "79305a826f872fe446c6fbf8450f515053ef6951",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "c53a6ee88b0a91bd012ef1b7988c0b93dae6f24d",
                            "lessThan": "bf74aa86e111aa3b2fbb25db37e3a3fab71b5b68",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/can/bcm.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.29",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.29",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "4.19.226",
                            "lessThanOrEqual": "4.19.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.4",
                            "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": "2.6.29",
                                    "versionEndExcluding": "4.19.226"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "2.6.29",
                                    "versionEndExcluding": "5.4"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/79305a826f872fe446c6fbf8450f515053ef6951"
                },
                {
                    "url": "https://git.kernel.org/stable/c/bf74aa86e111aa3b2fbb25db37e3a3fab71b5b68"
                }
            ],
            "title": "can: bcm: switch timer to HRTIMER_MODE_SOFT and remove hrtimer_tasklet",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-07-27T13:44:24.567768Z",
                                "id": "CVE-2026-17523",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-07-27T13:44:45.277Z"
                }
            }
        ]
    }
}