CVE-2026-5366: prefecthq/prefect · Code Injection
Affects prefecthq/prefectSource CVE Database V5
Not known to be exploited · CVSS 9.9 Critical.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 1.0% chance of exploitation in 30 days – higher than 63% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
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), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| prefecthqprefecthq/prefect | Affected
| Fixed in– |
AI-suggested
Until an official fix is available, restrict deployment creation permissions to trusted users only and avoid using affected versions in sensitive environments. Monitor vendor channels for updates and apply patches promptly once released.
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.