Skip to content
Heist/ feed
Back to feed
HighFix available

staging: rtl8723bs: fix OOB write in HT_caps_handler()

Type: advisorySources: OSV

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB write in HT_caps_handler() HT_caps_handler() iterates pIE->length bytes and writes into HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct HT_caps_element). Because pIE->length is a raw u8 from an over-the-air 802.11 AssocResponse frame and is never validated, a malicious AP can set it up to 255, causing up to 229 bytes of out-of-bounds writes into adjacent fields of struct mlme_ext_info. Truncate the iteration count to the size of HT_caps.u.HT_cap using umin() so that data from a longer-than-expected IE is silently ignored rather than written out of bounds, preserving interoperability with APs that pad the element. An early return on oversized IEs was considered but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1 assignment that precedes the loop, silently disabling HT mode for APs that append extra bytes to the HT Capabilities IE.

Products
Kernel
Affected versions
Not specified
Fixed versions
5.15.212, 6.1.178, 6.12.96, 6.18.39, 6.6.145, 7.1.4
CVEs
CVE-2026-64440
Confirmed fixed CVEs
Not specified
Updated in this feed
3 Nov 2026, 11:35 UTC · Revision 1

Source evidence

staging: rtl8723bs: fix OOB write in HT_caps_handler()

core-osv · Original source

Published 25 Jul 2026, 08:51 UTC

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB write in HT_caps_handler() HT_caps_handler() iterates pIE->length bytes and writes into HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct HT_caps_element). Because pIE->length is a raw u8 from an over-the-air 802.11 AssocResponse frame and is never validated, a malicious AP can set it up to 255, causing up to 229 bytes of out-of-bounds writes into adjacent fields of struct mlme_ext_info. Truncate the iteration count to the size of HT_caps.u.HT_cap using umin() so that data from a longer-than-expected IE is silently ignored rather than written out of bounds, preserving interoperability with APs that pad the element. An early return on oversized IEs was considered but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1 assignment that precedes the loop, silently disabling HT mode for APs that append extra bytes to the HT Capabilities IE.

osv:CVE-2026-64440

Kernel

Fixed versions: 5.15.212, 6.1.178, 6.6.145, 6.12.96, 6.18.39, 7.1.4

Complete source record
{
  "id": "8396070d64183776c93a41635566b13d029717202681831f0880c6253a4b7acd",
  "url": "https://osv.dev/vulnerability/CVE-2026-64440",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "staging: rtl8723bs: fix OOB write in HT_caps_handler()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: staging: rtl8723bs: fix OOB write in HT_caps_handler() HT_caps_handler() iterates pIE->length bytes and writes into HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct HT_caps_element). Because pIE->length is a raw u8 from an over-the-air 802.11 AssocResponse frame and is never validated, a malicious AP can set it up to 255, causing up to 229 bytes of out-of-bounds writes into adjacent fields of struct mlme_ext_info. Truncate the iteration count to the size of HT_caps.u.HT_cap using umin() so that data from a longer-than-expected IE is silently ignored rather than written out of bounds, preserving interoperability with APs that pad the element. An early return on oversized IEs was considered but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1 assignment that precedes the loop, silently disabling HT mode for APs that append extra bytes to the HT Capabilities IE.",
    "evidence": "osv:CVE-2026-64440",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.212",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.178",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.145",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.96",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.39",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-64440",
      "aliases": [
        "CVE-2026-64440"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "554c0a3abf216c991c5ebddcdb2c08689ecd290b"
                },
                {
                  "fixed": "37f642d47c3648a707df3ceb092eee1adffbfd28"
                },
                {
                  "fixed": "8c872b47c7fc32e95e0da1db7512388794adcd69"
                },
                {
                  "fixed": "bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a"
                },
                {
                  "fixed": "918537a0fbed85aab61fa28ad75e6279070610c9"
                },
                {
                  "fixed": "6f91621fc45025ad3c0be796b70e6e4cee22fc69"
                },
                {
                  "fixed": "225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d"
                },
                {
                  "fixed": "f8001e1a516ba3b495728c65b61f799cbfad6bd0"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64440.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.12.0"
                },
                {
                  "fixed": "5.15.212"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.178"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.145"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.96"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.39"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64440.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:28.312022199Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/225b6d3fc7e99ac3d20b6c861d1e47d24e7ea31d",
        "https://git.kernel.org/stable/c/37f642d47c3648a707df3ceb092eee1adffbfd28",
        "https://git.kernel.org/stable/c/6f91621fc45025ad3c0be796b70e6e4cee22fc69",
        "https://git.kernel.org/stable/c/8c872b47c7fc32e95e0da1db7512388794adcd69",
        "https://git.kernel.org/stable/c/918537a0fbed85aab61fa28ad75e6279070610c9",
        "https://git.kernel.org/stable/c/bb3b942da4123b55d1cacf19d1a7d5ba15dbf83a",
        "https://git.kernel.org/stable/c/f8001e1a516ba3b495728c65b61f799cbfad6bd0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64440.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64440",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64440.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64440",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 495010,
  "published_at": "2026-07-25T08:51:13.138+00:00"
}