How severe is CVE-2021-43667?

CVE-2021-43667 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-43667 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43667?

CVE-2021-43667 primarily affects Linuxfoundation Fabric. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-43667?

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.

When was CVE-2021-43667 published?

CVE-2021-43667 was published on 2021-11-18 and last updated on 2026-06-17.

CVE-2021-43667

CVE-2021-43667 is a high-severity vulnerability in Linuxfoundation Fabric with a CVSS 3.x base score of 7.5. 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-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Linuxfoundation Fabric
Published: 2021-11-18
Last modified: 2026-06-17

Description

A vulnerability has been detected in HyperLedger Fabric v1.4.0, v2.0.0, v2.1.0. This bug can be leveraged by constructing a message whose payload is nil and sending this message with the method 'forwardToLeader'. This bug has been admitted and fixed by the developers of Fabric. If leveraged, any leader node will crash.

Frequently asked questions

What is CVE-2021-43667?: A vulnerability has been detected in HyperLedger Fabric v1.4.0, v2.0.0, v2.1.0. This bug can be leveraged by constructing a message whose payload is nil and sending this message with the method 'forwardToLeader'. This bug has been admitted and fixed by the developers of Fabric. If leveraged, any leader node will crash.
How severe is CVE-2021-43667?: CVE-2021-43667 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-43667 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43667?: CVE-2021-43667 primarily affects Linuxfoundation Fabric. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-43667?: 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.
When was CVE-2021-43667 published?: CVE-2021-43667 was published on 2021-11-18 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:linuxfoundation:fabric:1.4.0:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:fabric:2.0.0:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:fabric:2.1.0:*:*:*:*:*:*:*

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