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
CVE-2021-22600
Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2022-04-11), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 6.6 retained for reference. Confidence: HIGH.
- Actively exploited in the wild (CISA-KEV)
A fix is available — apply it.
- CVSS v3
- 6.6
- EG Score
- 9.0(high)
- EG Risk
- 81(Attend)EG Risk 81/100SSVC: Attend
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity90% × 45%Exploitation100% × 40%Automatability0% × 15%Action: Remediate soon — notable exploitation risk. - EPSS PROB
- 6%
- EPSS %ILE
- 93%
- KEV
- ⚠ Exploited
Published
January 26, 2022
Last Modified
October 24, 2025
Advisory Details (5)
Auto-updated Jun 12, 2026Known Exploited Vulnerabilities Catalog | CISA
Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22600[SECURITY] [DSA 5096-1] linux security update
https://www.debian.org/security/2022/dsa-5096[SECURITY] [DLA 2941-1] linux-4.19 security update
https://lists.debian.org/debian-lts-announce/2022/03/msg00012.htmlnet/packet: rx_owner_map depends on pg_vec - kernel/git/torvalds/linux.git - Linux kernel source tree
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=ec6af094ea28f0f2dda1a6a33b14cd57e36a9755Patch Availability(7)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | linux-buildinfo-5.14.0-1022-oem (5.14.0-1022.24) @ focal | 2026-09-08 | ubuntu |
| ubuntu | linux-image-lowlatency (5.4.0.100.104) @ focal | 2026-09-08 | ubuntu |
| ubuntu | linux-virtual-hwe-20.04 (5.13.0.30.33~20.04.17) @ focal | 2026-09-08 | ubuntu |
| ubuntu | linux-headers-5.13.0-30-generic-lpae (5.13.0-30.33) @ impish | 2026-09-08 | ubuntu |
| ubuntu | linux-image-ibm-edge (5.4.0.1015.32) @ bionic | 2026-09-08 | ubuntu |
| ubuntu | linux-azure-cloud-tools-4.15.0-1131 (4.15.0-1131.144~14.04.1) @ trusty | 2026-09-08 | ubuntu |
| ubuntu | linux-tools-5.4.0-1061-gke (5.4.0-1061.64) @ focal | 2026-09-08 | ubuntu |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(6 across 6 ecosystems)
Debian:10(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | 4.19.118-1 ... 4.19.98-1~bpo9+1 (36 versions) | 4.19.232-1 | — |
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | 5.10.46-4 ... 5.10.92-1~bpo10+1 (6 versions) | 5.10.92-1 | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.15.15-1 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.15.15-1 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.15.15-1 | — |
Debian:9(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux-4.19 | 4.19.132-1~deb9u1 ... 4.19.208-1~deb9u1 (10 versions) | 4.19.232-1~deb9u1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(8)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
- Microsoft MSRCCVE-2021-226002022-02-05
Double Free in net/packet/af_packet.c leading to priviledge escalation
- UbuntuUSN-5266-1HIGH
Linux kernel (GKE) vulnerabilities
- UbuntuUSN-5278-1HIGH
Linux kernel (OEM) vulnerabilities
- UbuntuUSN-5294-1HIGH
Linux kernel vulnerabilities
- UbuntuUSN-5294-2HIGH
Linux kernel vulnerabilities
- UbuntuUSN-5295-1HIGH
Linux kernel (HWE) vulnerabilities
- UbuntuUSN-5295-2HIGH
Linux kernel vulnerabilities
- UbuntuUSN-5298-1HIGH
Linux kernel vulnerabilities
Data Freshness Timeline
(refreshed 97× in last 7d / 415× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 1,362 total refreshes for this CVE.
- 2026-09-08 10:10 UTCVendor advisory
- 2026-09-08 10:10 UTCGHSA enrichment
- 2026-09-08 06:05 UTCVendor advisory
- 2026-09-08 06:04 UTCGHSA enrichment
- 2026-09-08 01:58 UTCVendor advisory
- 2026-09-08 01:57 UTCGHSA enrichment
- 2026-09-07 21:52 UTCVendor advisory
- 2026-09-07 21:51 UTCGHSA enrichment
- 2026-09-07 17:46 UTCEG score recompute
- 2026-09-07 17:46 UTCVendor advisory
- 2026-09-07 17:46 UTCGHSA enrichment
- 2026-09-07 15:58 UTCEPSS rescore
- 2026-09-07 13:41 UTCVendor advisory
- 2026-09-07 13:41 UTCGHSA enrichment
- 2026-09-07 09:34 UTCVendor advisory
- 2026-09-07 09:34 UTCGHSA enrichment
- 2026-09-07 05:27 UTCVendor advisory
- 2026-09-07 05:27 UTCGHSA enrichment
- 2026-09-07 01:22 UTCVendor advisory
- 2026-09-07 01:21 UTCGHSA enrichment
- 2026-09-06 21:16 UTCVendor advisory
- 2026-09-06 21:16 UTCGHSA enrichment
- 2026-09-06 17:11 UTCEG score recompute
- 2026-09-06 17:11 UTCVendor advisory
- 2026-09-06 17:10 UTCGHSA enrichment
Show 75 moreShow fewer
- 2026-09-06 13:44 UTCEPSS rescore
- 2026-09-06 13:44 UTCEPSS rescore
- 2026-09-06 13:05 UTCVendor advisory
- 2026-09-06 13:04 UTCGHSA enrichment
- 2026-09-06 08:59 UTCVendor advisory
- 2026-09-06 08:59 UTCGHSA enrichment
- 2026-09-06 04:54 UTCVendor advisory
- 2026-09-06 04:54 UTCGHSA enrichment
- 2026-09-06 00:49 UTCVendor advisory
- 2026-09-06 00:49 UTCGHSA enrichment
- 2026-09-05 20:44 UTCVendor advisory
- 2026-09-05 20:43 UTCGHSA enrichment
- 2026-09-05 16:38 UTCEG score recompute
- 2026-09-05 16:38 UTCVendor advisory
- 2026-09-05 16:38 UTCGHSA enrichment
- 2026-09-05 15:25 UTCEPSS rescore
- 2026-09-05 12:32 UTCVendor advisory
- 2026-09-05 12:32 UTCGHSA enrichment
- 2026-09-05 08:27 UTCVendor advisory
- 2026-09-05 08:27 UTCGHSA enrichment
- 2026-09-05 04:21 UTCVendor advisory
- 2026-09-05 04:21 UTCGHSA enrichment
- 2026-09-05 00:16 UTCVendor advisory
- 2026-09-05 00:15 UTCGHSA enrichment
- 2026-09-04 20:09 UTCVendor advisory
- 2026-09-04 20:09 UTCGHSA enrichment
- 2026-09-04 17:38 UTCCISA KEV update
- 2026-09-04 16:03 UTCEG score recompute
- 2026-09-04 16:03 UTCVendor advisory
- 2026-09-04 16:02 UTCGHSA enrichment
- 2026-09-04 13:57 UTCEPSS rescore
- 2026-09-04 11:57 UTCVendor advisory
- 2026-09-04 11:57 UTCGHSA enrichment
- 2026-09-04 07:51 UTCEG score recompute
- 2026-09-04 07:51 UTCVendor advisory
- 2026-09-04 07:51 UTCGHSA enrichment
- 2026-09-04 05:03 UTCEPSS rescore
- 2026-09-04 03:45 UTCVendor advisory
- 2026-09-04 03:45 UTCGHSA enrichment
- 2026-09-03 23:39 UTCVendor advisory
- 2026-09-03 23:39 UTCGHSA enrichment
- 2026-09-03 19:30 UTCVendor advisory
- 2026-09-03 19:30 UTCGHSA enrichment
- 2026-09-03 15:25 UTCVendor advisory
- 2026-09-03 15:25 UTCGHSA enrichment
- 2026-09-03 11:19 UTCVendor advisory
- 2026-09-03 11:18 UTCGHSA enrichment
- 2026-09-03 07:13 UTCVendor advisory
- 2026-09-03 07:12 UTCGHSA enrichment
- 2026-09-03 03:07 UTCVendor advisory
- 2026-09-03 03:07 UTCGHSA enrichment
- 2026-09-02 23:01 UTCVendor advisory
- 2026-09-02 23:01 UTCGHSA enrichment
- 2026-09-02 18:55 UTCGHSA enrichment
- 2026-09-02 17:33 UTCCISA KEV update
- 2026-09-02 14:46 UTCEG score recompute
- 2026-09-02 14:46 UTCVendor advisory
- 2026-09-02 14:46 UTCGHSA enrichment
- 2026-09-02 14:08 UTCEPSS rescore
- 2026-09-02 10:41 UTCVendor advisory
- 2026-09-02 10:40 UTCGHSA enrichment
- 2026-09-02 06:34 UTCVendor advisory
- 2026-09-02 06:33 UTCGHSA enrichment
- 2026-09-02 02:28 UTCVendor advisory
- 2026-09-02 02:28 UTCGHSA enrichment
- 2026-09-01 22:19 UTCVendor advisory
- 2026-09-01 22:19 UTCGHSA enrichment
- 2026-09-01 18:14 UTCVendor advisory
- 2026-09-01 18:14 UTCGHSA enrichment
- 2026-09-01 14:09 UTCEG score recompute
- 2026-09-01 14:09 UTCVendor advisory
- 2026-09-01 14:08 UTCGHSA enrichment
- 2026-09-01 13:50 UTCEPSS rescore
- 2026-09-01 10:02 UTCVendor advisory
- 2026-09-01 10:02 UTCGHSA enrichment
Frequently asked(6)
What is CVE-2021-22600?
When was CVE-2021-22600 disclosed?
Is CVE-2021-22600 actively exploited?
What is the CVSS score of CVE-2021-22600?
Which products are affected by CVE-2021-22600?
How do I remediate CVE-2021-22600?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-22600
Is Your Infrastructure Affected by CVE-2021-22600?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.