What is CVE-2021-22600?

CVE-2021-22600 is a medium-severity vulnerability in Linux Kernel, classified under Double Free. CVSS score: 6.6/10. Published 2022-01-26.

How severe is CVE-2021-22600?

Medium severity. CVSS v3 base score is 6.6 out of 10.

Is CVE-2021-22600 known to be exploited?

Yes. CVE-2021-22600 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-04-11), indicating it is being actively exploited. 14 public proof-of-concept repositories are indexed.

Double Free in Linux Kernel

CVE-2021-22600

A double free bug in packet_set_ring() in net/packet/af_packet.c can be exploited by a local user through crafted syscalls to escalate privileges or deny service. We recommend upgrading kernel past the effected versions or rebuilding past ec6af094ea28f0f2dda1a6a33b14cd57e36a9755

Vulnerability class: Double Free

Published 2022-01-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.6 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:H.

EPSS exploit prediction

EPSS: 0.066 (93.8th percentile), scored 2026-10-18.

Low probability of exploitation in the next 30 days, but still tracked. 94th percentile — 93.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.061 · newest: 0.066 · change: +0.005

Affected products

Weakness classification (CWE)

CWE-415 — Double Free

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-04-11. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-05-02.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit (Patch, Mailing List)
lists.debian.org/debian-lts-announce/2022/03/msg00012.html (mailing-list, Mailing List, Third Party Advisory)
www.debian.org/security/2022/dsa-5096 (vendor-advisory, Third Party Advisory)
security.netapp.com/advisory/ntap-20230110-0002/ (Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2021-22600?: CVE-2021-22600 is a medium-severity vulnerability in Linux Kernel, classified under Double Free. CVSS score: 6.6/10. Published 2022-01-26.
How severe is CVE-2021-22600?: Medium severity. CVSS v3 base score is 6.6 out of 10.
Is CVE-2021-22600 known to be exploited?: Yes. CVE-2021-22600 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-04-11), indicating it is being actively exploited. 14 public proof-of-concept repositories are indexed.