Answer in brief
CVE-2026-64539 records a High severity (CVSS 7.8) vulnerability in Bluetooth: eir: Fix stack OOB write when prepending the Flags AD. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), 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), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=b44133ff03be30b55f23036e62f403a3f7784fce <0f0b6232af56441d0a2dcb173cc4f8d8aab39014 || >=b44133ff03be30b55f23036e62f403a3f7784fce <09301f1fdf2aef8cce34d0c4650c30e7edb1ced9 || >=b44133ff03be30b55f23036e62f403a3f7784fce <f1b4df9c260c51726da2e86e19322825fddeefd0 || >=b44133ff03be30b55f23036e62f403a3f7784fce <57077eeb586c42f124bc09e018449362223067b3 || >=b44133ff03be30b55f23036e62f403a3f7784fce <6f5fb689fdf80bdd143f22a502f9eb1f3c85e286 | 0f0b6232af56441d0a2dcb173cc4f8d8aab39014, 09301f1fdf2aef8cce34d0c4650c30e7edb1ced9, f1b4df9c260c51726da2e86e19322825fddeefd0, 57077eeb586c42f124bc09e018449362223067b3, 6f5fb689fdf80bdd143f22a502f9eb1f3c85e286 |
| Linux/Linuxgeneric | 4.1 | Not reported |
| Linux/Linuxgeneric | >=b44133ff03be30b55f23036e62f403a3f7784fce <0f0b6232af56441d0a2dcb173cc4f8d8aab39014 || >=b44133ff03be30b55f23036e62f403a3f7784fce <9174992ee1045c9c96e53eecda64f49dd7e8fbba || >=b44133ff03be30b55f23036e62f403a3f7784fce <09301f1fdf2aef8cce34d0c4650c30e7edb1ced9 || >=b44133ff03be30b55f23036e62f403a3f7784fce <f1b4df9c260c51726da2e86e19322825fddeefd0 || >=b44133ff03be30b55f23036e62f403a3f7784fce <57077eeb586c42f124bc09e018449362223067b3 || >=b44133ff03be30b55f23036e62f403a3f7784fce <6f5fb689fdf80bdd143f22a502f9eb1f3c85e286 | 0f0b6232af56441d0a2dcb173cc4f8d8aab39014, 9174992ee1045c9c96e53eecda64f49dd7e8fbba, 09301f1fdf2aef8cce34d0c4650c30e7edb1ced9, f1b4df9c260c51726da2e86e19322825fddeefd0, 57077eeb586c42f124bc09e018449362223067b3, 6f5fb689fdf80bdd143f22a502f9eb1f3c85e286 |
Published upstream
Jul 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: eir: Fix stack OOB write when prepending the Flags AD eir_create_adv_data() builds the advertising data into a fixed-size buffer ("size", 31 for the legacy path). It may prepend a 3-byte "Flags" AD structure (LE_AD_NO_BREDR on an LE-only controller) and then copies the per-instance data without checking that it still fits: memcpy(ptr, adv->adv_data, adv->adv_data_len); tlv_data_max_len() only reserves those 3 bytes when the user-supplied flags carry a managed-flags bit, so an instance added with flags == 0 is accepted with adv_data_len up to the full buffer. At advertise time the flags are still prepended, and the memcpy() writes 3 + adv_data_len bytes into the size-byte buffer: BUG: KASAN: stack-out-of-bounds in eir_create_adv_data (net/bluetooth/eir.c:301) Write of size 31 at addr ffff88800a547bdc by task kworker/u9:0/65 Workqueue: hci0 hci_cmd_sync_work __asan_memcpy (mm/kasan/shadow.c:106) eir_create_adv_data (net/bluetooth/eir.c:301) hci_update_adv_data_sync (net/bluetooth/hci_sync.c:1310) hci_schedule_adv_instance_sync (net/bluetooth/hci_sync.c:1817) hci_cmd_sync_work (net/bluetooth/hci_sync.c:332) This frame has 1 object: [32, 64) 'cp' The "Flags" structure is added by the kernel, not requested by userspace, so only prepend it when it fits together with the instance advertising data; when there is no room for both, drop the flags rather than the user-provided data. Reachable by a local user with CAP_NET_ADMIN owning an LE-only controller on the legacy advertising path.
Quoted source text, attributed separately from HOL analysis.