{"id":"CVE-2026-64440","state":"PUBLISHED","title":"staging: rtl8723bs: fix OOB write in HT_caps_handler()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix OOB write in HT_caps_handler()\n\nHT_caps_handler() iterates pIE->length bytes and writes into\nHT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct\nHT_caps_element). Because pIE->length is a raw u8 from an over-the-air\n802.11 AssocResponse frame and is never validated, a malicious AP can\nset it up to 255, causing up to 229 bytes of out-of-bounds writes into\nadjacent fields of struct mlme_ext_info.\n\nTruncate the iteration count to the size of HT_caps.u.HT_cap using\numin() so that data from a longer-than-expected IE is silently ignored\nrather than written out of bounds, preserving interoperability with APs\nthat pad the element. An early return on oversized IEs was considered\nbut rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1\nassignment that precedes the loop, silently disabling HT mode for APs\nthat append extra bytes to the HT Capabilities IE.","publishedAt":"2026-07-25T08:51:13.138Z","updatedAt":"2026-10-19T20:38:29.179Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"37f642d47c3648a707df3ceb092eee1adffbfd28","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"8c872b47c7fc32e95e0da1db7512388794adcd69","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"918537a0fbed85aab61fa28ad75e6279070610c9","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"6f91621fc45025ad3c0be796b70e6e4cee22fc69","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"f8001e1a516ba3b495728c65b61f799cbfad6bd0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/staging/rtl8723bs/core/rtw_wlan_util.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/staging/rtl8723bs/core/rtw_wlan_util.c"]}],"references":["https://git.kernel.org/stable/c/37f642d47c3648a707df3ceb092eee1adffbfd28","https://git.kernel.org/stable/c/8c872b47c7fc32e95e0da1db7512388794adcd69","https://git.kernel.org/stable/c/bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a","https://git.kernel.org/stable/c/918537a0fbed85aab61fa28ad75e6279070610c9","https://git.kernel.org/stable/c/6f91621fc45025ad3c0be796b70e6e4cee22fc69","https://git.kernel.org/stable/c/225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d","https://git.kernel.org/stable/c/f8001e1a516ba3b495728c65b61f799cbfad6bd0"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64440.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64440","state":"PUBLISHED","datePublished":"2026-07-25T08:51:13.138Z","dateUpdated":"2026-10-19T20:38:29.179Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.788Z"},"containers":{"cna":{"title":"staging: rtl8723bs: fix OOB write in HT_caps_handler()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix OOB write in HT_caps_handler()\n\nHT_caps_handler() iterates pIE->length bytes and writes into\nHT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct\nHT_caps_element). Because pIE->length is a raw u8 from an over-the-air\n802.11 AssocResponse frame and is never validated, a malicious AP can\nset it up to 255, causing up to 229 bytes of out-of-bounds writes into\nadjacent fields of struct mlme_ext_info.\n\nTruncate the iteration count to the size of HT_caps.u.HT_cap using\numin() so that data from a longer-than-expected IE is silently ignored\nrather than written out of bounds, preserving interoperability with APs\nthat pad the element. An early return on oversized IEs was considered\nbut rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1\nassignment that precedes the loop, silently disabling HT mode for APs\nthat append extra bytes to the HT Capabilities IE."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"37f642d47c3648a707df3ceb092eee1adffbfd28","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"8c872b47c7fc32e95e0da1db7512388794adcd69","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"918537a0fbed85aab61fa28ad75e6279070610c9","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"6f91621fc45025ad3c0be796b70e6e4cee22fc69","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d","versionType":"git"},{"version":"554c0a3abf216c991c5ebddcdb2c08689ecd290b","status":"affected","lessThan":"f8001e1a516ba3b495728c65b61f799cbfad6bd0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/staging/rtl8723bs/core/rtw_wlan_util.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/staging/rtl8723bs/core/rtw_wlan_util.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/37f642d47c3648a707df3ceb092eee1adffbfd28"},{"url":"https://git.kernel.org/stable/c/8c872b47c7fc32e95e0da1db7512388794adcd69"},{"url":"https://git.kernel.org/stable/c/bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a"},{"url":"https://git.kernel.org/stable/c/918537a0fbed85aab61fa28ad75e6279070610c9"},{"url":"https://git.kernel.org/stable/c/6f91621fc45025ad3c0be796b70e6e4cee22fc69"},{"url":"https://git.kernel.org/stable/c/225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d"},{"url":"https://git.kernel.org/stable/c/f8001e1a516ba3b495728c65b61f799cbfad6bd0"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - A nearby attacker can transmit a crafted 802.11 association response over the air; WiFi management-frame injection requires radio proximity and is not routable.\nAC:L - A malicious AP controls the IE length, contents, and handshake timing, making the bit-clearing overwrite deterministic without a race or uncontrollable condition.\nPR:N - The frame is processed before WPA or 802.1X credential verification, and OnAssocRsp does not authenticate its source BSSID; no target privilege or network credential is required.\nUI:N - Mobile, embedded, and headless systems commonly associate or roam automatically, allowing an evil-twin AP to reach the handler without human action.\nS:U - The corruption affects host-kernel driver state without crossing a VM, IOMMU, sandbox, or other security-authority boundary.\nC:N - The primitive only AND-clears following HT and network metadata and cannot reach pointer-bearing fields; no secret-bearing read or attacker-visible disclosure path was found.\nI:H - The oversized IE causes up to 229 attacker-controlled bit-mask writes beyond the 26-byte array, corrupting live kernel HT information and saved network metadata.\nA:H - The attacker can repeatedly corrupt BSSID, SSID, rate, IE-length, and HT state to prevent association; on a WiFi-dependent controller or IoT device this can sustain total loss of connectivity."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:55:42.056Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64440","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:40:46.718780Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","type":"CWE","description":"CWE-787 Out-of-bounds Write"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:29.179Z"}}]}}}