bluez: Passkey Entry protocol of the Bluetooth Core is vulnerable to an impersonation attack
Published May 24, 2021
4.2
MEDIUMCVSS 3.1
EPSS 0.87%
Description
Bluetooth LE and BR/EDR secure pairing in Bluetooth Core Specification 2.1 through 5.2 may permit a nearby man-in-the-middle attacker to identify the Passkey used during pairing (in the Passkey authentication procedure) by reflection of the public key and the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. The attack methodology determines the Passkey value one bit at a time.
Affected products
No data.
Configuration 1
- ≥ 2.1 · ≤ 5.2
Configuration 2
- 34
Configuration 3
- 9.0
Configuration 4
- < 5.13
Configuration 5
- n/a
Configuration 6
- n/a
Configuration 7
- n/a
Configuration 8
- n/a
Configuration 9
- n/a
Configuration 10
- n/a
Configuration 11
- n/a
Configuration 12
- n/a
Configuration 13
- n/a
Configuration 14
- n/a
Configuration 15
- n/a
Configuration 16
- n/a
Configuration 17
- n/a
Configuration 18
- n/a
Configuration 19
- n/a
No data.
Red Hat Enterprise Linux 8
bluez-0:5.56-1.el8
Fixed · RHSA-2021:4432
Red Hat Enterprise Linux 8
bluez-0:5.56-1.el8
Fixed · RHSA-2021:4432
Red Hat Enterprise Linux 6
bluez
Not affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
bluez
Out of support scope
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Will not fix
Red Hat Enterprise Linux 8
kernel-rt
Will not fix
Red Hat Enterprise Linux 9
bluez
Not affected
Red Hat Enterprise Linux 9
kernel
Not affected
Red Hat Enterprise Linux 9
kernel-rt
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | bluez-0:5.56-1.el8 | Fixed | RHSA-2021:4432 |
| Red Hat Enterprise Linux 8 | bluez-0:5.56-1.el8 | Fixed | RHSA-2021:4432 |
| Red Hat Enterprise Linux 6 | bluez | Not affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | bluez | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Will not fix | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Will not fix | n/a |
| Red Hat Enterprise Linux 9 | bluez | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | n/a |
No package ranges for this CVE.
Remediation
Red Hat statement
Red Hat Product Security is aware of this issue and is currently assessing the impact on Red Hat supported products. Corresponding entry in the Red Hat CVE database (https://access.redhat.com/security/security-updates/#/cve) will be updated with latest information as the assessment progresses.
Red Hat mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
No CVSS v3.0 score for this CVE.
AV:A/AC:M/Au:N/C:P/I:P/A:N
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Percentile over time
- EPSS v1
- EPSS v5
- EPSS v2
- EPSS v3
- EPSS v4
Table of values (17 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.87% (0.00872) | 57.39th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.87% (0.00872) | 53.99th | v5 (v2026.06.15) |
| Mar 17, 2025 | 0.02% (0.00018) | 2.67th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.07% (0.00066) | 31.39th | v3 (v2023.03.01) |
| Jun 12, 2024 | 0.07% (0.00067) | 29.27th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.07% (0.00067) | 27.24th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.54% (0.01537) | 72.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 5.13% (0.05132) | 75.07th | v2 (v2022.01.01) |
| Feb 3, 2022 | 8.66% (0.08659) | 85.81th | v1 |
| Jan 6, 2022 | 8.66% (0.08659) | 85.64th | v1 |
| Oct 11, 2021 | 2.07% (0.02069) | 77.54th | v1 |
| Oct 10, 2021 | 8.66% (0.08659) | 92.89th | v1 |
| Aug 8, 2021 | 8.66% (0.08659) | 0.00th | v1 |
| Aug 7, 2021 | 1.86% (0.01865) | 0.00th | v1 |
| Jun 23, 2021 | 1.66% (0.01659) | 0.00th | v5 (v2026.06.15) |
| May 25, 2021 | 0.62% (0.00624) | 0.00th | v1 |
References (16)
- https://access.redhat.com/security/cve/CVE-2020-26558 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1918602 Issue Tracking
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6d19628f539fccf899298ff02ee4c73e4bf6df3f
- https://kb.cert.org/vuls/id/799380 x_refsource_MISCThird Party AdvisoryUS Government Resource
- https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2021/06/msg00022.html mailing-listx_refsource_MLISTMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NSS6CTGE4UGTJLCOZOASDR3T3SLL6QJZ/ vendor-advisoryx_refsource_FEDORA
- https://nvd.nist.gov/vuln/detail/CVE-2020-26558
- https://security.gentoo.org/glsa/202209-16 vendor-advisoryx_refsource_GENTOOThird Party Advisory
- https://www.bluetooth.com/learn-about-bluetooth/key-attributes/bluetooth-security/reporting-security/ x_refsource_MISCVendor Advisory
- https://www.cve.org/CVERecord?id=CVE-2020-26558
- https://www.debian.org/security/2021/dsa-4951 vendor-advisoryx_refsource_DEBIANThird Party Advisory
- https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00517.html x_refsource_CONFIRMThird Party Advisory
- https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-00520.html x_refsource_CONFIRMThird Party Advisory
- https://www.kb.cert.org/vuls/id/799380
Change history (0)
No recorded changes yet.