Is CVE-2026-5366 in the CISA KEV catalog?

No. CVE-2026-5366 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-5366?

CVE-2026-5366 has a CVSS v3 base score of 9.9 (CRITICAL).

What is the EPSS score for CVE-2026-5366?

CVE-2026-5366 has an EPSS score of 0.57% (43th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-5366

CRITICAL

9.9

CVSS v3

NVD

Description

Prefect version 3.6.23 is vulnerable to remote code execution due to improper handling of user-controlled input in the `GitRepository` storage class. The `commit_sha` parameter, which is passed to git commands, lacks validation and does not include a `--` separator to distinguish user input from git flags. This allows attackers to inject arbitrary git flags, such as `--upload-pack`, enabling execution of external programs. Additionally, the `directories` parameter can be exploited to inject git flags during sparse-checkout operations. These vulnerabilities allow any user with deployment creation permissions to execute arbitrary commands on worker machines, compromising shared work pools in multi-tenant environments.

CWE-94Code Injection

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploit Intelligence

0.57%probability of exploitation in 30 days

43rdpercentile

Moderate risk: more likely to be exploited than 43% of all known CVEs.

References

https://huntr.com/bounties/e2e88a0f-a8f6-49c9-94c5-e98dc385f07a

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-22.