How severe is CVE-2026-3514?

CVE-2026-3514 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 high, integrity none, and availability none.

Is CVE-2026-3514 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3514?

CVE-2026-3514 affects Prefect. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3514?

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.

Does CVE-2026-3514 have an EU (EUVD) identifier?

Yes. CVE-2026-3514 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33884.

When was CVE-2026-3514 published?

CVE-2026-3514 was published on 2026-06-02 and last updated on 2026-06-17.

CVE-2026-3514

CVE-2026-3514 is a high-severity vulnerability in Prefect 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-863.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-33884
Weakness: CWE-863
Affected product: Prefect
Published: 2026-06-02
Last modified: 2026-06-17

Description

In version 3.6.19 of prefecthq/prefect, an authentication bypass vulnerability exists due to the improper handling of URL path exemptions for health check probes. Specifically, the authentication middleware exempts any URL path ending with 'health' or 'ready' from authentication checks. This allows an attacker to create resources with names ending in 'health' or 'ready' and access them without authentication. Affected endpoints include those for variables, flows, work pools, work queues, and deployments. This vulnerability can lead to unauthorized access to sensitive information, such as API keys and database credentials, stored in Prefect Variables.

Frequently asked questions

What is CVE-2026-3514?: In version 3.6.19 of prefecthq/prefect, an authentication bypass vulnerability exists due to the improper handling of URL path exemptions for health check probes. Specifically, the authentication middleware exempts any URL path ending with 'health' or 'ready' from authentication checks. This allows an attacker to create resources with names ending in 'health' or 'ready' and access them without authentication. Affected endpoints include those for variables, flows, work pools, work queues, and deployments. This vulnerability can lead to unauthorized access to sensitive information, such as API keys and database credentials, stored in Prefect Variables.
How severe is CVE-2026-3514?: CVE-2026-3514 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 high, integrity none, and availability none.
Is CVE-2026-3514 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3514?: CVE-2026-3514 affects Prefect. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3514?: 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.
Does CVE-2026-3514 have an EU (EUVD) identifier?: Yes. CVE-2026-3514 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33884.
When was CVE-2026-3514 published?: CVE-2026-3514 was published on 2026-06-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:prefect:prefect:*:*:*:*:*:*:*:*

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