GHSA-39C4-67X8-FP8M
Vulnerability from github – Published: 2026-08-15 15:30 – Updated: 2026-08-23 15:33In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: HIDP: reject frames without a transaction header
hidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb->data[0] before checking that the L2CAP SDU contains a transaction header. A connected HIDP peer can send an empty basic-mode SDU and make both paths use an uninitialized byte from skb tailroom.
KMSAN reports the use in hidp_session_run(), with the uninitialized value originating in __alloc_skb() through vhci_write(). The control path produces two reports and the interrupt path produces one.
The byte can also be controlled by a malformed lower-layer packet. If an HCI ACL packet contains an L2CAP PDU with a declared zero-length payload followed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb->len to the declared PDU length before dispatch. The current HIDP path nevertheless consumes the extra byte as HIDP_TRANS_HID_CONTROL | HIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this change, the same packet is discarded and a subsequent feature report request succeeds.
Pull the transaction header with skb_pull_data() and discard frames that do not contain it.
{
"affected": [],
"aliases": [
"CVE-2026-74508"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T13:17:55Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: HIDP: reject frames without a transaction header\n\nhidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb-\u003edata[0]\nbefore checking that the L2CAP SDU contains a transaction header. A\nconnected HIDP peer can send an empty basic-mode SDU and make both paths\nuse an uninitialized byte from skb tailroom.\n\nKMSAN reports the use in hidp_session_run(), with the uninitialized value\noriginating in __alloc_skb() through vhci_write(). The control path\nproduces two reports and the interrupt path produces one.\n\nThe byte can also be controlled by a malformed lower-layer packet. If an\nHCI ACL packet contains an L2CAP PDU with a declared zero-length payload\nfollowed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb-\u003elen to\nthe declared PDU length before dispatch. The current HIDP path nevertheless\nconsumes the extra byte as HIDP_TRANS_HID_CONTROL |\nHIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this\nchange, the same packet is discarded and a subsequent feature report\nrequest succeeds.\n\nPull the transaction header with skb_pull_data() and discard frames that\ndo not contain it.",
"id": "GHSA-39c4-67x8-fp8m",
"modified": "2026-08-23T15:33:02Z",
"published": "2026-08-15T15:30:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74508"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/238c333bc4b3f245c626632e8bfa3c9dab97f51b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/24c64ccd5c1fc9934b427335b0d976c7f2b1a7d8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2ebf63aa557a69990b4e9ea22be224d58aabce96"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/46ca5ab39737d7c6f9ca77ecf714cdcfa6caaeec"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/47778d2c2087b5d192398f6fddf692d16a5431cf"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/567a2a0a633f2ea5fdccaf3517c09f22c9d860c7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/854194494a6f726a60b90b76059148bf08df023d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/97b61241ab45bfa5b0526cb0f3978942493bc811"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.