How severe is CVE-2021-47668?

CVE-2021-47668 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-47668 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47668?

CVE-2021-47668 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-47668?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-47668 have an EU (EUVD) identifier?

Yes. CVE-2021-47668 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34679.

When was CVE-2021-47668 published?

CVE-2021-47668 was published on 2025-04-17 and last updated on 2026-06-17.

CVE-2021-47668

CVE-2021-47668 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34679
Weakness: CWE-416
Affected product: Linux Linux Kernel
Published: 2025-04-17
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: can: dev: can_restart: fix use after free bug After calling netif_rx_ni(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is accessed after the netif_rx_ni() in: stats->rx_bytes += cf->len; Reordering the lines solves the issue.

Frequently asked questions

What is CVE-2021-47668?: In the Linux kernel, the following vulnerability has been resolved: can: dev: can_restart: fix use after free bug After calling netif_rx_ni(skb), dereferencing skb is unsafe. Especially, the can_frame cf which aliases skb memory is accessed after the netif_rx_ni() in: stats->rx_bytes += cf->len; Reordering the lines solves the issue.
How severe is CVE-2021-47668?: CVE-2021-47668 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-47668 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47668?: CVE-2021-47668 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-47668?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-47668 have an EU (EUVD) identifier?: Yes. CVE-2021-47668 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34679.
When was CVE-2021-47668 published?: CVE-2021-47668 was published on 2025-04-17 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.11:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.11:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.11:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.11:rc4:*:*:*:*:*:*

More vulnerabilities in Linux Linux Kernel

CVE-2023-2163 — Critical (CVSS 10.0): Incorrect verifier pruning in BPF in Linux Kernel >=5.4 leads to unsafe code paths being incorrectly marked as safe,…
CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-1421 — Critical (CVSS 10.0): Use-after-free vulnerability in the sctp_assoc_update function in net/sctp/associola.c in the Linux kernel before…
CVE-2014-2523 — Critical (CVSS 10.0): net/netfilter/nf_conntrack_proto_dccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly,…
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2010-2521 — Critical (CVSS 10.0): Multiple buffer overflows in fs/nfsd/nfs4xdr.c in the XDR implementation in the NFS server in the Linux kernel before…

All CVEs affecting Linux Linux Kernel →

Other CWE-416 (Use After Free) vulnerabilities

CVE-2026-13782 — Critical (CVSS 10.0): Use after free in Browser in Google Chrome prior to 150.0.7871.47 allowed a remote attacker who had compromised the…
CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
CVE-2025-24085 — Critical (CVSS 10.0): A use after free issue was addressed with improved memory management. This issue is fixed in iOS 18.3 and iPadOS 18.3,…
CVE-2024-43102 — Critical (CVSS 10.0): Concurrent removals of certain anonymous shared memory mappings by using the UMTX_SHM_DESTROY sub-request of…
CVE-2021-32495 — Critical (CVSS 10.0): Radare2 has a use-after-free vulnerability in pyc parser's get_none_object function. Attacker can read freed memory…

Browse all CWE-416 (Use After Free) vulnerabilities →