VulnerabilityPublished 4 May 2026

CVE-2026-7722: PrefectHQ prefect · Improper Authentication

Affects PrefectHQ prefectSource CVE Database V5

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Public exploit available · CVSS 6.9 Medium · fixed in 3.6.22 : patch PrefectHQ prefect as a priority.

Data as of 31 Oct 2026, 20:20 UTC

CVSS 4.0 base score

6.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.6.22

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

Base metrics

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Threat metrics

Exploit Maturity: POC

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
PrefectHQprefect	Affected 3.6.0 – 3.6.21 22 affected builds	Fixed in–
PyPIprefect`pkg:pypi/prefect`Other threats	Affected 3.6.0 – 3.6.21 22 affected builds	Fixed in–

CPE configurations (1)

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

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AI-suggested

Upgrade PrefectHQ prefect to version 3.6.22 or later to remediate this vulnerability. Since the vendor has released a fixed version, applying this official update is the recommended mitigation. Patch status is confirmed by the advisory stating upgrading to 3.6.22 fixes the issue.

Description

A vulnerability was detected in PrefectHQ prefect up to 3.6.21. This impacts the function endswith of the file /api/health of the component Health Check API. Performing a manipulation results in improper authentication. The attack is possible to be carried out remotely. The exploit is now public and may be used. Upgrading to version 3.6.22 will fix this issue. The patch is named e21617125335025b4b27e7d6f0ca028e8e8f3b79. Upgrading the affected component is recommended. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

Impact

Successful exploitation allows remote attackers to bypass authentication on the Health Check API endpoint, potentially granting unauthorized access to health check information or related functionality. The impact is limited to improper authentication without direct evidence of further privilege escalation or data compromise in the provided data.

Summary

This vulnerability affects PrefectHQ prefect versions 3.6.0 through 3.6.21. The issue lies in the Health Check API's /api/health endpoint, where improper authentication occurs due to a flaw in the endswith function. This allows unauthenticated remote attackers to bypass authentication controls. The vulnerability has a CVSS 4.0 base score of 6.9, indicating medium severity. A public exploit exists. The vendor has released version 3.6.22 which fixes this vulnerability.

References

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