Use After Free vulnerability in nfc sockets in the Linux Kernel before 5.12.4 allows local attackers to elevate their privileges. In typical configurations, the issue can only be triggered by a privileged local user with the CAP_NET_RAW capability.
CVE-2021-23134
This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 73% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.8
- EG Score
- 7.8(medium)
- EG Risk
- 40(Track)EG Risk 40/100SSVC: Track
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 computedSeverity78% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 29%
- KEV
- Not listed
Published
May 12, 2021
Last Modified
July 30, 2026
Advisory Details (7)
Auto-updated Jul 30, 2026[SECURITY] [DLA 2689-1] linux security update
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html[SECURITY] [DLA 2690-1] linux-4.19 security update
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.htmlnet/nfc: fix use-after-free llcp_sock_bind/connect - kernel/git/netdev/net.git - Netdev Group's networking tree
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=c61760e6940doss-security - CVE-2021-23134: Linux kernel: UAF in nfc sockets
https://www.openwall.com/lists/oss-security/2021/05/11/4[SECURITY] Fedora 33 Update: kernel-5.11.20-200.fc33 - package-announce - Fedora mailing-lists
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QALNQT4LJFVSSA3MWCIECVY4AFPP4X77/[SECURITY] Fedora 34 Update: kernel-tools-5.11.20-300.fc34 - package-announce - Fedora mailing-lists
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LZYORWNQIHNWRFYRDXBWYWBYM46PDZEN/Vendor Advisories for CVE-2021-23134(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(8)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | linux-image-unsigned-5.11.0-1009-kvm (5.11.0-1009.9) @ hirsute | 2026-05-26 | ubuntu |
| ubuntu | linux-image-lowlatency (5.11.0.22.23) @ hirsute | 2026-05-26 | ubuntu |
| ubuntu | linux-image-raspi2-hwe-18.04 (5.4.0.1038.73) @ focal | 2026-05-26 | ubuntu |
| ubuntu | linux-image-oem-20.04-edge (5.10.0.1033.34) @ focal | 2026-05-26 | ubuntu |
| ubuntu | linux-modules-5.4.0-1041-kvm (5.4.0-1041.42) @ focal | 2026-05-26 | ubuntu |
| ubuntu | vlan-modules-4.15.0-151-generic-di (4.15.0-151.157~16.04.1) @ xenial | 2026-05-26 | ubuntu |
| ubuntu | kernel-image-5.8.0-63-generic-lpae-di (5.8.0-63.71) @ groovy | 2026-05-26 | ubuntu |
| ubuntu | linux-image-lowlatency (4.4.0.222.229) @ xenial | 2026-05-26 | 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 5 ecosystems)
Debian:9(2)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | 4.9.107-1 ... 4.9.88-1~bpo8+1 (66 versions) | 4.9.272-1 | — |
| linux-4.19 | 4.19.132-1~deb9u1 ... 4.19.181-1~deb9u1 (7 versions) | 4.19.194-1~deb9u1 | — |
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.10.38-1 | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.10.38-1 | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.10.38-1 | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| linux | — | 5.10.38-1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(9)
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-2021-231342021-05-21
Linux kernel llcp_sock_bind/connect use-after-free
- UbuntuUSN-4997-1MEDIUM
Linux kernel vulnerabilities
- UbuntuUSN-4997-2MEDIUM
Linux kernel (KVM) vulnerabilities
- UbuntuUSN-5000-1MEDIUM
Linux kernel vulnerabilities
- UbuntuUSN-5000-2MEDIUM
Linux kernel (KVM) vulnerabilities
- UbuntuUSN-5001-1MEDIUM
Linux kernel (OEM) vulnerabilities
- UbuntuUSN-5016-1MEDIUM
Linux kernel vulnerabilities
- UbuntuUSN-5018-1MEDIUM
Linux kernel vulnerabilities
- UbuntuUSN-5343-1MEDIUM
Linux kernel vulnerabilities
Data Freshness Timeline
(refreshed 8× in last 7d / 31× 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 169 total refreshes for this CVE.
- 2026-09-24 14:00 UTCEPSS rescore
- 2026-09-24 14:00 UTCEPSS rescore
- 2026-09-23 13:44 UTCEPSS rescore
- 2026-09-22 14:44 UTCEPSS rescore
- 2026-09-21 20:28 UTCEPSS rescore
- 2026-09-20 05:38 UTCOSV refresh
- 2026-09-19 15:37 UTCEPSS rescore
- 2026-09-18 19:23 UTCEPSS rescore
- 2026-09-17 19:23 UTCEPSS rescore
- 2026-09-16 14:05 UTCEPSS rescore
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- 2026-09-15 03:06 UTCEPSS rescore
- 2026-09-13 16:43 UTCEPSS rescore
- 2026-09-12 14:57 UTCEPSS rescore
- 2026-09-11 09:33 UTCEPSS rescore
- 2026-09-10 09:29 UTCEPSS rescore
- 2026-09-08 21:56 UTCEPSS rescore
- 2026-09-07 15:58 UTCEPSS rescore
- 2026-09-06 13:44 UTCEPSS rescore
- 2026-09-06 13:44 UTCEPSS rescore
- 2026-09-05 15:25 UTCEPSS rescore
- 2026-09-04 13:57 UTCEPSS rescore
- 2026-09-04 05:03 UTCEPSS rescore
- 2026-09-02 14:08 UTCEPSS rescore
- 2026-09-01 13:50 UTCEPSS rescore
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- 2026-09-01 08:59 UTCOSV refresh
- 2026-09-01 03:32 UTCEPSS rescore
- 2026-08-30 19:14 UTCEPSS rescore
- 2026-08-30 01:19 UTCEPSS rescore
- 2026-08-28 21:37 UTCEPSS rescore
- 2026-08-27 14:22 UTCEPSS rescore
- 2026-08-26 14:42 UTCEPSS rescore
- 2026-08-25 13:45 UTCEPSS rescore
- 2026-08-23 00:16 UTCEPSS rescore
- 2026-08-21 23:46 UTCEPSS rescore
- 2026-08-20 22:52 UTCEPSS rescore
- 2026-08-19 17:01 UTCEPSS rescore
- 2026-08-18 13:45 UTCEPSS rescore
- 2026-08-17 13:43 UTCEPSS rescore
- 2026-08-16 14:52 UTCEPSS rescore
- 2026-08-16 02:11 UTCEPSS rescore
- 2026-08-15 08:37 UTCOSV refresh
- 2026-08-15 01:27 UTCEPSS rescore
- 2026-08-13 21:57 UTCEPSS rescore
- 2026-08-12 13:47 UTCEPSS rescore
- 2026-08-11 13:38 UTCEPSS rescore
- 2026-08-09 13:43 UTCEPSS rescore
- 2026-08-08 16:33 UTCEPSS rescore
- 2026-08-07 16:23 UTCEPSS rescore
- 2026-08-06 13:43 UTCEPSS rescore
- 2026-08-05 19:14 UTCEPSS rescore
- 2026-08-04 15:06 UTCEPSS rescore
- 2026-08-04 10:34 UTCEPSS rescore
- 2026-08-03 10:32 UTCEPSS rescore
- 2026-08-02 02:24 UTCEPSS rescore
- 2026-08-01 04:12 UTCEPSS rescore
- 2026-07-30 20:25 UTCEG score recompute
- 2026-07-30 20:25 UTCVendor advisory
- 2026-07-30 20:25 UTCGHSA enrichment
- 2026-07-30 16:25 UTCEPSS rescore
- 2026-07-30 01:27 UTCEPSS rescore
- 2026-07-30 01:27 UTCEPSS rescore
- 2026-07-26 14:52 UTCEPSS rescore
- 2026-07-25 14:15 UTCEPSS rescore
- 2026-07-24 14:15 UTCEPSS rescore
- 2026-07-23 14:15 UTCEPSS rescore
- 2026-07-23 01:57 UTCEG score recompute
- 2026-07-22 22:44 UTCEG score recompute
- 2026-07-22 14:05 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-21 15:22 UTCEPSS rescore
- 2026-07-20 17:04 UTCEPSS rescore
- 2026-07-19 14:28 UTCEPSS rescore
- 2026-07-19 02:26 UTCEPSS rescore
- 2026-07-18 20:59 UTCOSV refresh
- 2026-07-18 10:02 UTCEPSS rescore
- 2026-07-16 17:00 UTCEPSS rescore
- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-15 16:55 UTCEPSS rescore
- 2026-07-15 01:57 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 22:27 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-13 06:10 UTCEPSS rescore
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-12 05:44 UTCEPSS rescore
- 2026-07-11 08:25 UTCEPSS rescore
- 2026-07-09 19:07 UTCEPSS rescore
- 2026-07-08 15:12 UTCEPSS rescore
- 2026-07-07 13:43 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-06 02:21 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
- 2026-07-05 02:28 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-04 06:29 UTCEPSS rescore
- 2026-07-02 16:57 UTCEPSS rescore
- 2026-07-01 15:03 UTCEPSS rescore
- 2026-07-01 03:48 UTCOSV refresh
- 2026-06-30 23:20 UTCEPSS rescore
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:9:linux-4.19
Same vendor
10 shownubuntu:USN-4997-1
Same CWE
10 shownCWE-416
- CVE-2021-20181EG 7.5HIGH
- CVE-2021-21822EG 8.8HIGH
- CVE-2021-28664NVD 8.8EG 9.0 KEVEPSS p92CRITICAL
- CVE-2021-28663NVD 8.8EG 9.0 KEVEPSS p96CRITICAL
- CVE-2021-1927EG 8.4HIGH
- CVE-2021-1905NVD 8.4EG 9.0 KEVCRITICAL
- CVE-2021-1891EG 8.4HIGH
- CVE-2021-20204EG 9.8CRITICAL
- CVE-2021-29256NVD 8.8EG 9.0 KEVCRITICAL
- CVE-2021-21232EG 8.8HIGH
Frequently asked(5)
What is CVE-2021-23134?
When was CVE-2021-23134 disclosed?
Is CVE-2021-23134 actively exploited?
What is the CVSS score of CVE-2021-23134?
How do I remediate CVE-2021-23134?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2021-23134
Is Your Infrastructure Affected by CVE-2021-23134?
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