CVE-2026-64539
HIGH 7.8 ALL-YEARSIn 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
Severe if exploited (CVSS 7.8), but no confirmed exploitation. Patch on a normal cadence.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 2nd percentile
Impact if exploited
7.8CVSS 3.1 · HIGH · CNA
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Weakness (CWE)
- CWE-121: Stack-based Buffer Overflow
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References and research data (JSON)
Vendor product assessments
Showing 32 of 276 vendor product statements; 244 omitted. Read the full vendor advisory.
kernel as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel
- none available: Affected
kernel-core as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-core
- none available: Affected
kernel-modules-extra-matched as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-modules-extra-matched
- none available: Affected
kernel-rt-debug as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-debug
- none available: Affected
kernel-uki-virt as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-uki-virt
- none available: Affected
kernel as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel
- none available: Affected
kernel-modules as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-modules
- none available: Affected
kernel-rt-modules-internal as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-modules-internal
- none available: Affected
python3-perf as a component of Red Hat Enterprise Linux 8 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/python3-perf
- none available: Affected
kernel-64k-modules as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-64k-modules
- none available: Affected
kernel-debug-modules-internal as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-debug-modules-internal
- none available: Affected
kernel-rt-64k as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k
- none available: Affected
kernel-rt-64k-modules as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-64k-modules
- none available: Affected
kernel-rt-devel as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-rt-devel
- none available: Affected
kernel-uki-virt-addons as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/kernel-uki-virt-addons
- none available: Affected
rv as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/rv
- none available: Affected
kernel as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-debug as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-debug
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-devel as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-devel
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-headers as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-headers
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel.src as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel?arch=src
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00bpftool as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/bpftool
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-abi-whitelists as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-abi-whitelists
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-debug-devel
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-headers as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-headers
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-rt as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-rt-debug-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-debug-devel
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-rt-doc as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-doc
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-rt-trace-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-rt-trace-devel
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-tools as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-tools
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00kernel-tools-libs-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/kernel-tools-libs-devel
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00python-perf as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/python-perf
Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
All CVSS metrics
- HIGH 7.8 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - HIGH 7.8 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
Advisories
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64539.json Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-49590 EUVD · EUVD-2026-49590
Technical & other
- https://git.kernel.org/stable/c/0f0b6232af56441d0a2dcb173cc4f8d8aab39014CVE record · Linux · Updated 2026-10-21T12:43:26.591Z
NVD · CVE-2026-64539 · Updated 2026-10-21T13:19:24.220 - https://git.kernel.org/stable/c/9174992ee1045c9c96e53eecda64f49dd7e8fbbaCVE record · Linux · Updated 2026-10-21T12:43:26.591Z
NVD · CVE-2026-64539 · Updated 2026-10-21T13:19:24.220 - https://git.kernel.org/stable/c/09301f1fdf2aef8cce34d0c4650c30e7edb1ced9CVE record · Linux · Updated 2026-10-21T12:43:26.591Z
NVD · CVE-2026-64539 · Updated 2026-10-21T13:19:24.220 - https://git.kernel.org/stable/c/f1b4df9c260c51726da2e86e19322825fddeefd0CVE record · Linux · Updated 2026-10-21T12:43:26.591Z
NVD · CVE-2026-64539 · Updated 2026-10-21T13:19:24.220 - https://git.kernel.org/stable/c/57077eeb586c42f124bc09e018449362223067b3CVE record · Linux · Updated 2026-10-21T12:43:26.591Z
NVD · CVE-2026-64539 · Updated 2026-10-21T13:19:24.220 - https://git.kernel.org/stable/c/6f5fb689fdf80bdd143f22a502f9eb1f3c85e286CVE record · Linux · Updated 2026-10-21T12:43:26.591Z
NVD · CVE-2026-64539 · Updated 2026-10-21T13:19:24.220 - https://access.redhat.com/security/cve/CVE-2026-64539 Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2507790 Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-64539 Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-64539 Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
- https://lore.kernel.org/linux-cve-announce/2026072735-CVE-2026-64539-4b67@gregkh/T Red Hat · CVE-2026-64539 · Updated 2026-10-23T11:18:33+00:00
Sources: NVD · CVE.org · All sources and attribution · EPSS