How severe is CVE-2021-27862?

CVE-2021-27862 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-27862 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27862?

CVE-2021-27862 primarily affects Ieee Ieee 802.2. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27862?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-27862 published?

CVE-2021-27862 was published on 2022-09-27 and last updated on 2026-06-17.

CVE-2021-27862

CVE-2021-27862 is a medium-severity vulnerability in Ieee Ieee 802.2 with a CVSS 3.x base score of 4.7. 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-290.

Key facts

Severity: Medium (CVSS 3.x base score 4.7)
EPSS exploit prediction: 1% (46th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-290
Affected product: Ieee Ieee 802.2
Published: 2022-09-27
Last modified: 2026-06-17

Description

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion (and optionally VLAN0 headers).

Frequently asked questions

What is CVE-2021-27862?: Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion (and optionally VLAN0 headers).
How severe is CVE-2021-27862?: CVE-2021-27862 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-27862 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27862?: CVE-2021-27862 primarily affects Ieee Ieee 802.2. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27862?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27862 published?: CVE-2021-27862 was published on 2022-09-27 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:ieee:ieee_802.2:*:*:*:*:*:*:*:*
cpe:2.3:a:ietf:p802.1q:*:*:*:*:*:*:*:*

More vulnerabilities in Ieee Ieee 802.2

CVE-2021-27861 — Medium (CVSS 4.7): Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length…
CVE-2021-27854 — Medium (CVSS 4.7): Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using combinations of VLAN 0 headers,…
CVE-2021-27853 — Medium (CVSS 4.7): Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of…

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