Container Hardening Bypass in Gitea's act_runner Docker Integration
CVE-2026-58053

9.4CRITICAL

Key Information:

Vendor

Gitea

Status
Act Runner
Vendor
CVE Published:
28 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-58053?

The Gitea act_runner component, specifically when utilized with the Docker backend through act version 0.262.0, is susceptible to a container hardening bypass. This vulnerability arises due to the manner in which the runner processes the container.options string within a workflow. Although the setup can enforce 'privileged: false', it inadequately restricts other host capabilities and settings, allowing users with workflow execution permissions to create job containers that access host namespaces and inherit extensive capabilities. Consequently, this could enable attackers to escape the container environment and gain unauthorized root access to the host system.

Affected Version(s)

act_runner 0 <= 0.262.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-58053 - Proof of Concept

References

https://github.com/bikini/exploitarium/tree/main/gitea-ac...
exploitthird-party-advisory
https://www.vulncheck.com/advisories/gitea-act-runner-con...
third-party-advisory

CVSS V4

Score:
9.4
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ashdfrkl
.