{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-74433",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-15T05:44:03.896Z",
        "datePublished": "2026-08-15T05:59:32.823Z",
        "dateUpdated": "2026-08-17T05:47:07.711Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-17T05:47:07.711Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix UAF in rxgk_issue_challenge()\n\nFix rxgk_issue_challenge() to free the page containing the challenge\ncontent after invoking the tracepoint as the whdr passed to the tracepoint\npoints into the page just freed."
                }
            ],
            "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 bug is in rxgk_issue_challenge() on the RxRPC server path reached when a remote UDP RxRPC DATA packet starts a new call; packets enter via rxrpc_encap_rcv() and the I/O thread, then conn_event processing issues an RxGK challenge during the pre-auth handshake on internet-facing AFS/RxGK servers.\nAC:L - Once an RxGK-enabled AFS kernel server is reachable, an attacker can reliably trigger rxgk_issue_challenge() by sending a valid incoming DATA packet with security index YFS-RxGK; the UAF is deterministic on each successful challenge transmission and does not depend on winning a race.\nPR:N - The vulnerable code runs during initial server-side connection setup before client credentials are verified: an unauthenticated remote peer that can reach the RxRPC UDP port can force challenge issuance without any local account, capability, or namespace privilege on the target.\nUI:N - Exploitation requires only network packets to the RxRPC listener; no victim user action such as opening files, mounting AFS, or enabling tracing is needed for the server to automatically enter the challenging path and hit the bug.\nS:U - Impact is confined to kernel memory integrity and availability on the AFS/RxRPC server host; it does not by itself cross a VM, container, or IOMMU security boundary, though it may enable local privilege escalation on that host.\nC:H - This is a use-after-free: __free_page() releases the challenge buffer before trace_rxrpc_tx_packet() dereferences whdr pointing into that page, enabling reads of freed slab/page memory and potential disclosure of kernel heap contents exploitable for KASLR bypass.\nI:H - UAF on the challenge transmit path can be leveraged with heap grooming to obtain controlled reuse of the freed page and build arbitrary kernel write or control-flow hijack primitives, not merely a bounded protocol corruption.\nA:H - Reading or reusing freed kernel pages during challenge handling can provoke kernel oops/panic or wedged RxRPC/AFS service state; repeated remote triggering of the handshake can deny availability of the file service even without full exploitation."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/rxrpc/rxgk.c"
                    ],
                    "versions": [
                        {
                            "version": "9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a",
                            "lessThan": "844b8525ce503405c462ad67f750bec648720397",
                            "status": "affected",
                            "versionType": "git"
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                        {
                            "version": "9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a",
                            "lessThan": "83bb0ed050e2ad9453d8ef50e4d6e624eac6eed8",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a",
                            "lessThan": "107a4cb0d47e735830f852d83970d5c81f8e1e08",
                            "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/rxrpc/rxgk.c"
                    ],
                    "versions": [
                        {
                            "version": "6.16",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.16",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.40",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.5",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
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                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                                    "versionEndExcluding": "6.18.40"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "7.1.5"
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.16",
                                    "versionEndExcluding": "7.2"
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/844b8525ce503405c462ad67f750bec648720397"
                },
                {
                    "url": "https://git.kernel.org/stable/c/83bb0ed050e2ad9453d8ef50e4d6e624eac6eed8"
                },
                {
                    "url": "https://git.kernel.org/stable/c/107a4cb0d47e735830f852d83970d5c81f8e1e08"
                }
            ],
            "title": "rxrpc: Fix UAF in rxgk_issue_challenge()",
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}