How severe is CVE-2021-43786?

CVE-2021-43786 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-43786 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43786?

CVE-2021-43786 affects Nodebb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43786?

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

When was CVE-2021-43786 published?

CVE-2021-43786 was published on 2021-11-29 and last updated on 2026-06-17.

CVE-2021-43786

CVE-2021-43786 is a critical-severity vulnerability in Nodebb with a CVSS 3.x base score of 9.8. 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-287.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 5.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Nodebb
Published: 2021-11-29
Last modified: 2026-06-17

Description

Nodebb is an open source Node.js based forum software. In affected versions incorrect logic present in the token verification step unintentionally allowed master token access to the API. The vulnerability has been patch as of v1.18.5. Users are advised to upgrade as soon as possible.

Frequently asked questions

What is CVE-2021-43786?: Nodebb is an open source Node.js based forum software. In affected versions incorrect logic present in the token verification step unintentionally allowed master token access to the API. The vulnerability has been patch as of v1.18.5. Users are advised to upgrade as soon as possible.
How severe is CVE-2021-43786?: CVE-2021-43786 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-43786 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43786?: CVE-2021-43786 affects Nodebb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43786?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-43786 published?: CVE-2021-43786 was published on 2021-11-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nodebb:nodebb:*:*:*:*:*:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

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