How severe is CVE-2021-40855?

CVE-2021-40855 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-2021-40855 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40855?

CVE-2021-40855 affects Europa Technical Specifications For Digital Covid Certificates. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40855?

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-2021-40855 published?

CVE-2021-40855 was published on 2022-01-21 and last updated on 2026-06-17.

CVE-2021-40855

CVE-2021-40855 is a critical-severity vulnerability in Europa Technical Specifications For Digital Covid Certificates 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-295.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (47th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Europa Technical Specifications For Digital Covid Certificates
Published: 2022-01-21
Last modified: 2026-06-17

Description

The EU Technical Specifications for Digital COVID Certificates before 1.1 mishandle certificate governance. A non-production public key certificate could have been used in production.

Frequently asked questions

What is CVE-2021-40855?: The EU Technical Specifications for Digital COVID Certificates before 1.1 mishandle certificate governance. A non-production public key certificate could have been used in production.
How severe is CVE-2021-40855?: CVE-2021-40855 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-2021-40855 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (47th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40855?: CVE-2021-40855 affects Europa Technical Specifications For Digital Covid Certificates. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40855?: 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-2021-40855 published?: CVE-2021-40855 was published on 2022-01-21 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:europa:technical_specifications_for_digital_covid_certificates:*:*:*:*:*:*:*:*

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