Answer in brief
CVE-2026-31772 records a High severity (CVSS 7.8) vulnerability in Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=91d19383b7ed035e22165ae5c836e50bb9f95fbe <f5d446624345d309e7a4a1b27ea9f028d6a8c5d9 || >=42ecf1947135110ea08abeaca39741636f9a2285 <aba0aea354015794e8312dd7efe726967e58aefe || >=42ecf1947135110ea08abeaca39741636f9a2285 <eaf32002ca7b1ba51c9f140991fd9febe6de79f0 || >=42ecf1947135110ea08abeaca39741636f9a2285 <bc39a094730ce062fa034a529c93147c096cb488 || 8958e1cee4e2eac1a5b825caa4dd96ce9ed975dd || >=6.12.2 <6.12.81 || >=6.11.11 <6.12 | f5d446624345d309e7a4a1b27ea9f028d6a8c5d9, aba0aea354015794e8312dd7efe726967e58aefe, eaf32002ca7b1ba51c9f140991fd9febe6de79f0, bc39a094730ce062fa034a529c93147c096cb488, 6.12.81, 6.12 |
| Linux/Linuxgeneric | 6.13 | Not reported |
Published upstream
May 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 16, 2026
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix stack buffer overflow in hci_le_big_create_sync hci_le_big_create_sync() uses DEFINE_FLEX to allocate a struct hci_cp_le_big_create_sync on the stack with room for 0x11 (17) BIS entries. However, conn->num_bis can hold up to HCI_MAX_ISO_BIS (31) entries — validated against ISO_MAX_NUM_BIS (0x1f) in the caller hci_conn_big_create_sync(). When conn->num_bis is between 18 and 31, the memcpy that copies conn->bis into cp->bis writes up to 14 bytes past the stack buffer, corrupting adjacent stack memory. This is trivially reproducible: binding an ISO socket with bc_num_bis = ISO_MAX_NUM_BIS (31) and calling listen() will eventually trigger hci_le_big_create_sync() from the HCI command sync worker, causing a KASAN-detectable stack-out-of-bounds write: BUG: KASAN: stack-out-of-bounds in hci_le_big_create_sync+0x256/0x3b0 Write of size 31 at addr ffffc90000487b48 by task kworker/u9:0/71 Fix this by changing the DEFINE_FLEX count from the incorrect 0x11 to HCI_MAX_ISO_BIS, which matches the maximum number of BIS entries that conn->bis can actually carry.
Quoted source text, attributed separately from HOL analysis.