The Bluetooth BR/EDR specification up to and including version 5.1 permits sufficiently low encryption key length and does not prevent an attacker from influencing the key length negotiation. This allows practical brute-force attacks (aka "KNOB") that can decrypt traffic and inject arbitrary ciphertext without the victim noticing.
CVE-2019-9506
Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2022-05-24. NVD baseline CVSS 8.1; sources differ by 0.0.
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 8.1
- EG Score
- 8.1(medium)
- EG Risk
- 57(Track)EG Risk 57/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity81% × 45%Exploitation40% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 3%
- EPSS %ILE
- 85%
- KEV
- Not listed
Published
August 14, 2019
Last Modified
November 21, 2024
Advisory Details (8)
Auto-updated Sep 12, 2026Affected: Red Hat Enterprise Linux 7.
https://access.redhat.com/errata/RHSA-2019:3055Affected: Red Hat Enterprise Linux 7.5 Extended Update Support.
https://access.redhat.com/errata/RHSA-2019:2975Security Advisory - Key Negotiation of Bluetooth (KNOB) Vulnerability
http://www.huawei.com/en/psirt/security-advisories/huawei-sa-20190828-01-knob-enDepartment of Computer Science, University of Oxford: Publication - The KNOB is Broken: Exploiting Low Entropy in the Encryption Key Negotiation Of Bluetooth BR/EDR
http://www.cs.ox.ac.uk/publications/publication12404-abstract.htmlFull Disclosure: APPLE-SA-2019-8-13-4 Additional information for APPLE-SA-2019-7-22-5 tvOS 12.4
http://seclists.org/fulldisclosure/2019/Aug/15Full Disclosure: APPLE-SA-2019-8-13-3 Additional information for APPLE-SA-2019-7-22-4 watchOS 5.3
http://seclists.org/fulldisclosure/2019/Aug/14Full Disclosure: APPLE-SA-2019-8-13-2 Additional information for APPLE-SA-2019-7-22-1 iOS 12.4
http://seclists.org/fulldisclosure/2019/Aug/13Full Disclosure: APPLE-SA-2019-8-13-1 Additional information for APPLE-SA-2019-7-22-2 macOS Mojave 10.14.6, Security Update 2019-004 High Sierra, Security Update 2019-004 Sierra
http://seclists.org/fulldisclosure/2019/Aug/11Patch Availability(16)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | linux-image-virtual-hwe-16.04 (4.15.0.60.81) @ xenial | 2026-05-27 | ubuntu |
| ubuntu | linux-image-virtual (5.0.0.31.32) @ disco | 2026-05-27 | ubuntu |
| ubuntu | linux-image-aws-hwe (4.15.0.1047.47) @ xenial | 2026-05-27 | ubuntu |
| redhat | kernel-0:3.10.0-327.86.1.el7 | 2020-04-14 | redhat |
| redhat | kernel-0:4.18.0-80.15.1.el8_0 | 2020-01-22 | redhat |
| redhat | kernel-rt-0:4.18.0-147.rt24.93.el8 | 2019-11-05 | redhat |
| redhat | kernel-0:4.18.0-147.el8 | 2019-11-05 | redhat |
| redhat | kernel-alt-0:4.14.0-115.14.1.el7a | 2019-10-29 | redhat |
| redhat | kpatch-patch | 2019-10-29 | redhat |
| redhat | kernel-0:3.10.0-514.70.1.el7 | 2019-10-29 | redhat |
| redhat | kernel-0:3.10.0-957.38.1.el7 | 2019-10-29 | redhat |
| redhat | kernel-0:3.10.0-693.60.1.el7 | 2019-10-24 | redhat |
| redhat | kernel-rt-1:3.10.0-693.60.1.rt56.654.el6rt | 2019-10-22 | redhat |
| redhat | kernel-0:3.10.0-1062.4.1.el7 | 2019-10-16 | redhat |
| redhat | kernel-rt-0:3.10.0-1062.4.1.rt56.1027.el7 | 2019-10-16 | redhat |
| redhat | kernel-0:3.10.0-862.43.1.el7 | 2019-10-08 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(6 across 5 ecosystems)
Debian:8(2)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | 3.16.36-1 ... 3.16.72-1 (67 versions) | 3.16.74-1 | — |
| linux-4.9 | 4.9.110-1~deb8u1, 4.9.144-3.1~deb8u1, 4.9.168-1~deb8u1 | 4.9.189-3~deb8u1 | — |
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.2.6-1 | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.2.6-1 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.2.6-1 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.2.6-1 | — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(18)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
- Microsoft MSRCCVE-2019-95062019-08-13
Encryption Key Negotiation of Bluetooth Vulnerability
- Red HatRHSA-2019:2975IMPORTANT2019-08-10
RHSA-2019:2975 — Important
- Red HatRHSA-2019:3055IMPORTANT2019-08-10
RHSA-2019:3055 — Important
- Red HatRHSA-2019:3076IMPORTANT2019-08-10
RHSA-2019:3076 — Important
- Red HatRHSA-2019:3089IMPORTANT2019-08-10
RHSA-2019:3089 — Important
- Red HatRHSA-2019:3165IMPORTANT2019-08-10
RHSA-2019:3165 — Important
- Red HatRHSA-2019:3187IMPORTANT2019-08-10
RHSA-2019:3187 — Important
- Red HatRHSA-2019:3217IMPORTANT2019-08-10
RHSA-2019:3217 — Important
- Red HatRHSA-2019:3218IMPORTANT2019-08-10
RHSA-2019:3218 — Important
- Red HatRHSA-2019:3220IMPORTANT2019-08-10
RHSA-2019:3220 — Important
- Red HatRHSA-2019:3231IMPORTANT2019-08-10
RHSA-2019:3231 — Important
- Red HatRHSA-2019:3309IMPORTANT2019-08-10
RHSA-2019:3309 — Important
- Red HatRHSA-2019:3517IMPORTANT2019-08-10
RHSA-2019:3517 — Important
- Red HatRHSA-2020:0204IMPORTANT2019-08-10
RHSA-2020:0204 — Important
- Red HatRHSA-2020:1460IMPORTANT2019-08-10
RHSA-2020:1460 — Important
- UbuntuUSN-4115-1MEDIUM
Linux kernel vulnerabilities
- UbuntuUSN-4118-1MEDIUM
Linux kernel (AWS) vulnerabilities
- UbuntuUSN-4147-1MEDIUM
Linux kernel vulnerabilities
Data Freshness Timeline
(refreshed 5× in last 7d / 20× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 137 total refreshes for this CVE.
- 2026-09-18 19:23 UTCEPSS rescore
- 2026-09-17 19:22 UTCEPSS rescore
- 2026-09-16 14:04 UTCEPSS rescore
- 2026-09-15 03:06 UTCEPSS rescore
- 2026-09-12 14:56 UTCEPSS rescore
- 2026-09-11 14:48 UTCEPSS rescore
- 2026-09-11 09:32 UTCEPSS rescore
- 2026-09-08 21:55 UTCEPSS rescore
- 2026-09-08 06:22 UTCOSV refresh
- 2026-09-07 15:57 UTCEPSS rescore
- 2026-09-06 13:44 UTCEPSS rescore
- 2026-09-05 15:24 UTCEPSS rescore
- 2026-09-04 13:56 UTCEPSS rescore
- 2026-09-02 14:08 UTCEPSS rescore
- 2026-09-01 03:32 UTCEPSS rescore
- 2026-08-30 01:18 UTCEPSS rescore
- 2026-08-27 14:21 UTCEPSS rescore
- 2026-08-26 14:42 UTCEPSS rescore
- 2026-08-25 13:45 UTCEPSS rescore
- 2026-08-21 16:44 UTCOSV refresh
- 2026-08-19 17:00 UTCEPSS rescore
- 2026-08-18 13:44 UTCEPSS rescore
- 2026-08-17 13:43 UTCEPSS rescore
- 2026-08-15 01:26 UTCEPSS rescore
- 2026-08-13 21:57 UTCEPSS rescore
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- 2026-08-12 13:47 UTCEPSS rescore
- 2026-08-09 13:43 UTCEPSS rescore
- 2026-08-08 16:33 UTCEPSS rescore
- 2026-08-07 16:23 UTCEPSS rescore
- 2026-08-06 01:54 UTCOSV refresh
- 2026-08-05 19:13 UTCEPSS rescore
- 2026-08-04 15:05 UTCEPSS rescore
- 2026-08-04 10:34 UTCEPSS rescore
- 2026-08-03 10:32 UTCEPSS rescore
- 2026-08-02 02:23 UTCEPSS rescore
- 2026-08-01 04:12 UTCEPSS rescore
- 2026-07-30 16:24 UTCEPSS rescore
- 2026-07-30 01:27 UTCEPSS rescore
- 2026-07-28 15:32 UTCEPSS rescore
- 2026-07-26 14:51 UTCEPSS rescore
- 2026-07-25 14:14 UTCEPSS rescore
- 2026-07-24 14:14 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 01:47 UTCEG score recompute
- 2026-07-22 22:30 UTCEG score recompute
- 2026-07-22 14:05 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-20 09:32 UTCOSV refresh
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-18 10:02 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-16 16:59 UTCEPSS rescore
- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-15 01:57 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-11 08:24 UTCEPSS rescore
- 2026-07-11 08:24 UTCEPSS rescore
- 2026-07-09 19:06 UTCEPSS rescore
- 2026-07-08 15:11 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 16:25 UTCEPSS rescore
- 2026-07-06 02:20 UTCEPSS rescore
- 2026-07-06 02:20 UTCEPSS rescore
- 2026-07-05 02:27 UTCEPSS rescore
- 2026-07-04 06:28 UTCEPSS rescore
- 2026-07-03 04:35 UTCOSV refresh
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-06-30 23:20 UTCEPSS rescore
- 2026-06-29 14:03 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-28 04:54 UTCEPSS rescore
- 2026-06-27 03:06 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-24 14:03 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-19 19:23 UTCEPSS rescore
- 2026-06-19 19:23 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
Publicly available exploits
(1 reference)Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- GitHub PoCfrancozappa/knobFirst seen Aug 15, 2019
Key Negotiation Of Bluetooth (KNOB) attacks on Bluetooth BR/EDR and BLE [CVE-2019-9506]
Open source ↗
Frequently asked(5)
What is CVE-2019-9506?
When was CVE-2019-9506 disclosed?
Is CVE-2019-9506 actively exploited?
What is the CVSS score of CVE-2019-9506?
How do I remediate CVE-2019-9506?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2019-9506
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