Prefect has Git Flag Injection via commit_sha and directories Parameters Leading to Remote Code Execution (RCE)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-5366: 1.03% estimated exploitation activity in the next 30 days; percentile 63.90 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Prefect versions 3.1.11 through 3.6.24 are 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.

Published by the source

20 Jun 2026, 18:31 UTC

Last modified by the source

3 Nov 2026, 21:31 UTC

Source last checked

4 Nov 2026, 06:20 UTC

1. Revision 2 · amended · 4 Nov 2026

   Amended from osv record GHSA-7pm4-56h2-5rxr

2. Revision 1 · created · 3 Nov 2026

   Published from ghsa record GHSA-7pm4-56h2-5rxr

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# Patch Next advisory brief: CVE-2026-5366

Advisory: Prefect has Git Flag Injection via commit_sha and directories Parameters Leading to Remote Code Execution (RCE)
IDs: CVE-2026-5366, GHSA-7pm4-56h2-5rxr
Record: https://patchnext.com/advisories/cve-2026-5366 (revision 2, source checked 4 Nov 2026, 06:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: prefect 3.6.25. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI prefect: affected >= 3.1.11, < 3.6.25; fixed in 3.6.25

## Suggested inspection (read-only)
- `python -m pip show prefect`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on prefect.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7pm4-56h2-5rxr (GitHub-reviewed advisory GHSA-7pm4-56h2-5rxr lists affected ranges: PyPI prefect >=3.1.11 <3.6.25)
- Verified: https://osv.dev/vulnerability/GHSA-7pm4-56h2-5rxr (OSV record GHSA-7pm4-56h2-5rxr lists affected ranges: PyPI prefect >=3.1.11 <3.6.25 (fixed))

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