How severe is CVE-2021-45890?

CVE-2021-45890 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-2021-45890 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45890?

CVE-2021-45890 affects Authguard Project Authguard. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45890?

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-2021-45890 published?

CVE-2021-45890 was published on 2021-12-27 and last updated on 2026-06-17.

CVE-2021-45890

CVE-2021-45890 is a critical-severity vulnerability in Authguard Project Authguard 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: 7.5
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Authguard Project Authguard
Published: 2021-12-27
Last modified: 2026-06-17

Description

basic/BasicAuthProvider.java in AuthGuard before 0.9.0 allows authentication via an inactive identifier.

Frequently asked questions

What is CVE-2021-45890?: basic/BasicAuthProvider.java in AuthGuard before 0.9.0 allows authentication via an inactive identifier.
How severe is CVE-2021-45890?: CVE-2021-45890 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-2021-45890 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45890?: CVE-2021-45890 affects Authguard Project Authguard. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45890?: 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-2021-45890 published?: CVE-2021-45890 was published on 2021-12-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:authguard_project:authguard:*:*:*:*:*:*:*:*

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