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Fencer Vulns
high 7.5

CVE-2020-26556 json

Mesh Provisioning in the Bluetooth Mesh profile 1.0 and 1.0.1 may permit a nearby device, able to conduct a successful brute-force attack o…

published 2021-05-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19101

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 60%
public exploits
0
none known

Summary

Mesh Provisioning in the Bluetooth Mesh profile 1.0 and 1.0.1 may permit a nearby device, able to conduct a successful brute-force attack on an insufficiently random AuthValue before the provisioning procedure times out, to complete authentication by leveraging Malleable Commitment.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-26556 updated cvss 7.5

kernel: malleable commitment Bluetooth Mesh Provisioning

  • Red Hat Enterprise Linux 6 bluez, bluez-alsa, bluez-cups, bluez-libs, bluez-compat, bluez-gstreamer Red Hat Enterprise Linux 7 bluez, bluez-cups, bluez-libs, bluez-hid2hci
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 bluez, bluez-cups, bluez-libs, bluez-obexd, bluez-hid2hci Red Hat Enterprise Linux 9 bluez, bluez-cups, bluez-libs, bluez-obexd
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, kernel-alt, python-perf, +9 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +81 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.91% chance of exploitation in the next 30 days, higher than 60% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 2.9 AV:A/AC:M/Au:N/C:P/I:N/A:N

Classification

Weakness
  • CWE-307 Improper Restriction of Excessive Authentication Attempts

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.