CVE-2026-3514Public exploitNetwork attack vector

Unauthenticated data exposure via suffix-matched probe paths

Published Jun 2, 2026 · Updated Jun 2, 2026

Authentication bypass in Prefect before 3.6.22 allows remote attackers to read protected API resources through crafted HTTP requests. The token-validation middleware in src/prefect/server/api/server.py treats any GET path ending in health or ready as an unauthenticated probe instead of matching only the probe paths. A reachable self-hosted server with API basic authentication enabled exposes matching variables, flows, work pools, work queues, or deployments, including secrets stored in variables.

CVSS severity7.5
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Prefect before 3.6.22 allows remote attackers to read protected API resources through crafted HTTP requests. The token-validation middleware in src/prefect/server/api/server.py treats any GET path ending in health or ready as an unauthenticated probe instead of matching only the probe paths. A reachable self-hosted server with API basic authentication enabled exposes matching variables, flows, work pools, work queues, or deployments, including secrets stored in variables.

The record

CVE
CVE-2026-3514
Published
Jun 2, 2026
Updated
Jun 2, 2026
Vendor
Prefect Technologies, Inc.
Product
Prefect
Classifications
CWE-863, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <3.6.22

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Prefect Technologies, Inc. · Prefectversion=unspecified <3.6.22

Published CVSS scores

7.5huntr.devCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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