{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90372", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.808Z", "datePublished": "2026-09-17T16:09:12.733Z", "dateUpdated": "2026-10-19T09:02:31.113Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:02:31.113Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss\n\nIf a peer's VHT/HE MCS map has no supported spatial stream (all fields\n0x3), the loop exits with nss == 0 and the function returned (u8)-1 (255),\nwhich was then written into the firmware sta_rec_bf beamforming fields.\nClamp the result to 0." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:A - A nearby 802.11 peer supplies the malformed MCS map in the HE Capabilities MCS NSS field of an Association Request. hostapd's NL80211_CMD_NEW_STATION reaches ieee80211_add_station()→sta_link_apply_parameters(), which copies he_mcs_nss_supp; mt76_sta_state(AUTH→ASSOC) then calls mt7915_mcu_get_sta_nss() on that map. WiFi radio range is Adjacent.\nAC:L - The attacker sets every 2-bit NSS field in HE rx_mcs_80 or rx_mcs_160 to 0x3. mt7915_mcu_get_sta_nss() then leaves its nss=8..1 loop with nss==0 and returns (u8)-1 (255) on every association. mac80211 does not reject an all-0x3 HE MCS map (unlike the 0xFFFF VHT check in ieee80211_vht_cap_ie_to_sta_vht_cap()). No race is involved.\nPR:N - mt7915_mac_sta_event(MT76_STA_EVENT_ASSOC) runs from sta_info_move_state(IEEE80211_STA_ASSOC) when hostapd's NL80211_CMD_NEW_STATION sets ASSOCIATED, before AUTHORIZED (the WPA 4-way handshake). 802.11 Open System authentication does not require a PSK or SAE credential on this path.\nUI:N - The attacker transmits the Association Request. ieee80211_add_station() and mt7915_mcu_add_sta() run in the AP kernel with no operator action on the victim device.\nS:U - The underflowed NSS is stored in the kernel sta_rec_bf TLV and sent to the on-device mt7915 MCU via MCU_EXT_CMD(STA_REC_UPDATE). Impact stays in the same kernel/device authority; this is not a VM, IOMMU, or sandbox escape.\nC:N - mt7915_mcu_get_sta_nss() only derives a u8 from the peer MCS map. That 255 is stored in sta_rec_bf.ncol_gt_bw80 or ibf_ncol; ncol used to index matrix[4][4] is min()'d with nrow, so there is no kernel OOB read and nothing is returned over the air.\nI:L - mt7915_mcu_sta_bfer_he() writes the underflowed nss_mcs (255) directly to sta_rec_bf.ncol_gt_bw80 on 160 MHz, and the implicit-VHT path writes it to ibf_ncol, then mt7915_mcu_add_sta() sends that TLV to firmware. That is a limited corruption of the chip beamforming profile, not an arbitrary kernel write.\nA:H - ncol_gt_bw80 and ibf_ncol are NSS counts the mt7915 MCU uses as beamforming dimensions. 255 is far outside the 0–3 range implied by the driver's matrix[4][4], so the firmware can hang or crash and take the radio down, and the peer can retrigger it on every association." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/wireless/mediatek/mt76/mt7915/mcu.c" ], "versions": [ { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "2801477c36a19be4f549fe60e54995f03b0ea7b9", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "38f4d6323bcd65e41a691432eddabd2b03acdeee", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "25f753f7f620955a8a51e63e445d8b9076c51396", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "e63c6291ecddf94769ab91f9d8cdb6ca939f7fc6", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "85bd46ab7674b6d357f9a14791352c65fb09eee9", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "6ce78d04c7ea4b66838941b5a4232dd1ee0e2cc7", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "ecfd1a07e78c31d81322fb2d81dc468081cc3004", "status": "affected", "versionType": "git" }, { "version": "89029a85482cbcf68026a89fc974e8f6898d6b37", "lessThan": "4a2f4be532e3ea4e2b536e411793a05aaa51af25", "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/net/wireless/mediatek/mt76/mt7915/mcu.c" ], "versions": [ { "version": "5.8", "status": "affected" }, { "version": "0", "lessThan": "5.8", "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": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "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": "5.8", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/2801477c36a19be4f549fe60e54995f03b0ea7b9" }, { "url": "https://git.kernel.org/stable/c/38f4d6323bcd65e41a691432eddabd2b03acdeee" }, { "url": "https://git.kernel.org/stable/c/25f753f7f620955a8a51e63e445d8b9076c51396" }, { "url": "https://git.kernel.org/stable/c/e63c6291ecddf94769ab91f9d8cdb6ca939f7fc6" }, { "url": "https://git.kernel.org/stable/c/85bd46ab7674b6d357f9a14791352c65fb09eee9" }, { "url": "https://git.kernel.org/stable/c/6ce78d04c7ea4b66838941b5a4232dd1ee0e2cc7" }, { "url": "https://git.kernel.org/stable/c/ecfd1a07e78c31d81322fb2d81dc468081cc3004" }, { "url": "https://git.kernel.org/stable/c/4a2f4be532e3ea4e2b536e411793a05aaa51af25" } ], "title": "wifi: mt76: mt7915: avoid nss underflow in mt7915_mcu_get_sta_nss", "x_generator": { "engine": "bippy-1.2.0" } } } }