thunderbolt: Bound the DROM dual link port number before indexing sw->ports

published 2026-08-22 2 mo ago modified 2026-11-06 2 d ago also EUVD-2026-64522

cvss: —; not scored
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

tb_drom_parse_entry_port() validates the device-supplied header->index against sw->config.max_port_number before indexing sw->ports[], but the sibling field entry->dual_link_port_nr -- a 6-bit value also read from the DROM -- indexes the same array with no such check. A malicious or malformed Thunderbolt device can set dual_link_port_nr beyond the allocated sw->ports[] (max_port_number + 1 entries), producing an out-of-bounds tb_port pointer that is stored and later dereferenced.

Reject a port entry whose dual_link_port_nr exceeds max_port_number, the same bound already applied to header->index.

Patch / fix

fixed in 1 distros 3 links 8

Linux Linux 5.10.265, 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45, 7.1.9, 7.2

debian ubuntu suse

linux Debian 12 6.1.187-1
linux Debian 13 6.12.105-1
linux Debian 14 7.1.9-1
linux-6.12 Debian 12 6.12.107-1~deb12u1

debian advisories DEBIAN-CVE-2026-74585

linux Ubuntu 22.04 LTS 5.15.0-198.208
linux Ubuntu 26.04 LTS 7.0.0-42.42
linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
linux-gke Ubuntu 22.04 LTS 5.15.0-1113.119
linux-ibm Ubuntu 22.04 LTS 5.15.0-1111.115

ubuntu advisories UBUNTU-CVE-2026-74585

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-source Linux Micro 6.0 6.4.0-159998.55.1
kernel-default Linux Micro 6.0 6.4.0-159998.55.1
kernel-kvmsmall Linux Micro 6.0 6.4.0-159998.55.1
kernel-default-base Linux Micro 6.0 6.4.0-159998.55.1.159998.21.42
kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1
kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.90.1
kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.90.1
kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1

suse advisories SUSE-SU-2026:24550-1 SUSE-SU-2026:5091-1 SUSE-SU-2026:4687-1

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-2026-74585 updated 2026-11-05 cvss 4.6

kernel: thunderbolt: Bound the DROM dual link port number before indexing sw->ports

Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 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, +83 more Red Hat Enterprise Linux 10 kernel
affected: workaround, no fix available “Fix deferred”
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 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

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 d ago (2026-11-06)

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

Linux Linux

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2026-74585
NVD CVE-2026-74585

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.

Summary