In the Linux kernel 5.11 through 5.12.2, isotp_setsockopt in net/can/isotp.c allows privilege escalation to root by leveraging a use-after-…

published 2021-05-11 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-19446

cvss: 7.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits: 0; none known

In the Linux kernel 5.11 through 5.12.2, isotp_setsockopt in net/can/isotp.c allows privilege escalation to root by leveraging a use-after-free. (This does not affect earlier versions that lack CAN ISOTP SF_BROADCAST support.)

Patch / fix

fixed in 1 distros 2 links 2

linux linux_kernel 5.12.9

opensuse arch linux

kernel-source openSUSE Tumbleweed 5.14.6-1.4
kernel-source openSUSE Tumbleweed 6.6.17-1.1

opensuse advisories openSUSE-SU-2024:10728-1 openSUSE-SU-2024:13704-1

linux Arch Linux 5.12.9.arch1-1
linux-zen Arch Linux 5.12.9.zen1-1
linux-hardened Arch Linux 5.12.9.hardened1-1

arch linux advisories AVG-2031 AVG-2032 AVG-2033

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-2021-32606 updated 2026-11-07 cvss 7.8

kernel: isotp_setsockopt in net/can/isotp.c allows privilege escalation via use-after-free

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, +82 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

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.2	AV:L/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness

CWE-416 Use After Free

Technology feeds

Linux kernel rss critical rss

References

git.kernel.org /cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2b17c400aeb44daf041627722581ade527bb3c1d
openwall.com /lists/oss-security/2021/05/28/1
mailing-list, patch, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/HD3NJBG25AADVGPRC63RX2JOQBMPSWK4/
vendor-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/GI7Z7UBWBGD3ABNIL2DC7RQDCGA4UVQW/
vendor-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/73D53S4IZFPFQMRABMXXLW4AJK3EULDX/
vendor-advisory
openwall.com /lists/oss-security/2021/05/11/16
mailing-list, third-party-advisory
openwall.com /lists/oss-security/2021/05/12/1
mailing-list, third-party-advisory
openwall.com /lists/oss-security/2021/05/13/2
mailing-list, third-party-advisory
openwall.com /lists/oss-security/2021/05/14/1
mailing-list, third-party-advisory
security.netapp.com /advisory/ntap-20210625-0001/
third-party-advisory

Sources

CVE List CVE-2021-32606
NVD CVE-2021-32606

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