Vulnerabilities in pkg:golang/gitea.com/gitea/runner

PACKAGE
Advisory Identifier: GHSA-x4q3-gcj3-m6cf
Advisory Summary

CVE-2026-73802 is a CRITICAL (CVSS 9.9) workflow container.options passes host namespaces vulnerability (CWE-269: Improper Privilege Management) affecting gitea-runner libraries in the Go ecosystem. The issue involves workflow container.options passes host namespaces and capability flags to job container when privileged mode is disabled. Remediation is available by upgrading affected packages to version 1.0.9-0.20260731160927-34bfa1915022.

1 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:golang/gitea.com/gitea/runner

1 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:golang/gitea.com/gitea/runner. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-x4q3-gcj3-m6cf CVE-2026-73802 CRITICAL gitea-runner: workflow container.options passes host namespaces and capability flags to job container when privileged mode is disabled

CVE-2026-73802 at a Glance

CVE Identifier CVE-2026-73802
GHSA Identifier GHSA-x4q3-gcj3-m6cf
Severity CRITICAL
CVSS v3.1 Base Score 9.9
CWE Classification CWE-269: Improper Privilege Management
Affected Product gitea-runner
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 9.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-73802

To remediate this vulnerability, upgrade all affected gitea-runner dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

gitea.com/gitea/runner fixed: 1.0.9-0.20260731160927-34bfa1915022
Upgrade gitea.com/gitea/runner to 1.0.9-0.20260731160927-34bfa1915022
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for gitea.com/gitea/runner

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-73802, inspect your project dependencies for gitea-runner:

inspect dependencies for gitea.com/gitea/runner

Analyze the terminal output to locate any version of gitea-runner in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.9-0.20260731160927-34bfa1915022), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-269: Improper Privilege Management, where the product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. In gitea-runner, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary act_runner appends workflow-controlled `jobs.<job>.container.options` directly to the Docker HostConfig for the job container. When runner privileged mode is disabled, only `Privileged` is forced false. Host namespace flags, capability expansion, and security profile overrides from workflow YAML are preserved in the final HostConfig. A workflow author can enter host PID/IPC namespaces and execute commands on the runner host as root. ### Details Source-to-sink path in act_runner: - `ContainerSpec.Options` accepts workflow YAML `container.options` - `RunContext.options()` appends workflow options to runner-level container options - Job container is created with `Privileged: rc.Config.Privileged` but also with `Options: rc.options(ctx)` - `mergeContainerConfigs()` parses Docker CLI-style options into HostConfig - When privileged mode is disabled, only `copts.privileged` is forced false - `sanitizeConfig()` only filters `Binds` and `Mounts` - Preserved dangerous HostConfig fields: ```text Privileged=false PidMode=host IpcMode=host CapAdd=["ALL"] SecurityOpt=["seccomp=unconfined","apparmor=unconfined"] ``` Attacker workflow YAML: ```yaml jobs: breakout: runs-on: ubuntu-latest container: image: ubuntu:22.04 options: >- --pid=host --ipc=host --cap-add=ALL --security-opt seccomp=unconfined --security-opt apparmor=unconfined steps: - name: host namespace marker run: | nsenter -t 1 -m -u -i -n -p -- sh -c "id > /tmp/marker" ``` ### Impact An attacker who can submit a workflow to a repository using a shared Docker-backed act_runner can: - Enter host PID, IPC, and mount namespaces - Execute arbitrary commands as root on the runner host - Access runner host secrets, deployment credentials, and environment variables - Pivot to adjacent jobs running on the same runner - Access internal build infrastructure reachable from the runner host Critical severity for shared runners where untrusted users can trigger workflows. High severity for single-tenant runners with privileged mode explicitly disabled as a security control. ### Fix Direction Treat `container.options` as untrusted input. Reject or strip when privileged mode is disabled: - Host namespaces: `--pid=host`, `--ipc=host`, `--uts=host`, `--network=host` - Capability expansion: `--cap-add ALL`, `--cap-add SYS_ADMIN` - Security overrides: `--security-opt seccomp=unconfined`, `--security-opt apparmor=unconfined` - Device access: `--device`, `--device-cgroup-rule` - Volume inheritance: `--volumes-from` - Runtime controls: `--runtime`, `--cgroup-parent`

CVE-2026-73802 Affected gitea-runner Versions

1 component(s)
Fixed Versions:
1.0.9-0.20260731160927-34bfa1915022
Product / Package Ecosystem Affected Versions Fixed Version
gitea.com/gitea/runner
Go
< 1.0.9-0.20260731160927-34bfa1915022
1.0.9-0.20260731160927-34bfa1915022

References

Frequently Asked Questions

What is CVE-2026-73802?
CVE-2026-73802 is a security vulnerability in gitea-runner involving workflow container.options passes host namespaces and capability flags to job container when privileged mode is disabled under CWE-269: Improper Privilege Management.
Which gitea-runner versions are affected?
Affected versions include releases prior to 1.0.9-0.20260731160927-34bfa1915022 across affected packages: gitea.com/gitea/runner.
What version fixes CVE-2026-73802?
Upgrading to 1.0.9-0.20260731160927-34bfa1915022 (or the latest patched release for your respective branch) resolves the vulnerability.
Is gitea.com/gitea/runner affected?
Yes, gitea.com/gitea/runner is affected in releases prior to 1.0.9-0.20260731160927-34bfa1915022. Upgrade your dependency to 1.0.9-0.20260731160927-34bfa1915022 or later.
What is the CVSS score of CVE-2026-73802?
CVE-2026-73802 has a CVSS v3.1 base score of 9.9 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-73802?
CVE-2026-73802 is classified under CWE-269: Improper Privilege Management (The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.).
How can I check Go dependencies for CVE-2026-73802?
Run the dependency tree command: 'inspect dependencies for gitea.com/gitea/runner'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x4q3-gcj3-m6cf",
  "modified" : "2026-10-02T23:18:12Z",
  "published" : "2026-10-02T23:18:12Z",
  "aliases" : [ "CVE-2026-73802" ],
  "summary" : "gitea-runner: workflow container.options passes host namespaces and capability flags to job container when privileged mode is disabled",
  "details" : "### Summary\nact_runner appends workflow-controlled `jobs.<job>.container.options` directly \nto the Docker HostConfig for the job container. When runner privileged mode is \ndisabled, only `Privileged` is forced false. Host namespace flags, capability \nexpansion, and security profile overrides from workflow YAML are preserved in \nthe final HostConfig. A workflow author can enter host PID/IPC namespaces and \nexecute commands on the runner host as root.\n\n### Details\nSource-to-sink path in act_runner:\n\n- `ContainerSpec.Options` accepts workflow YAML `container.options`\n- `RunContext.options()` appends workflow options to runner-level container options\n- Job container is created with `Privileged: rc.Config.Privileged` but also \n  with `Options: rc.options(ctx)`\n- `mergeContainerConfigs()` parses Docker CLI-style options into HostConfig\n- When privileged mode is disabled, only `copts.privileged` is forced false\n- `sanitizeConfig()` only filters `Binds` and `Mounts`\n- Preserved dangerous HostConfig fields:\n\n```text\nPrivileged=false\nPidMode=host\nIpcMode=host\nCapAdd=[\"ALL\"]\nSecurityOpt=[\"seccomp=unconfined\",\"apparmor=unconfined\"]\n```\n\nAttacker workflow YAML:\n```yaml\njobs:\n  breakout:\n    runs-on: ubuntu-latest\n    container:\n      image: ubuntu:22.04\n      options: >-\n        --pid=host --ipc=host --cap-add=ALL \n        --security-opt seccomp=unconfined \n        --security-opt apparmor=unconfined\n    steps:\n      - name: host namespace marker\n        run: |\n          nsenter -t 1 -m -u -i -n -p -- sh -c \"id > /tmp/marker\"\n```\n\n### Impact\nAn attacker who can submit a workflow to a repository using a shared \nDocker-backed act_runner can:\n\n- Enter host PID, IPC, and mount namespaces\n- Execute arbitrary commands as root on the runner host\n- Access runner host secrets, deployment credentials, and environment variables\n- Pivot to adjacent jobs running on the same runner\n- Access internal build infrastructure reachable from the runner host\n\nCritical severity for shared runners where untrusted users can trigger \nworkflows. High severity for single-tenant runners with privileged mode \nexplicitly disabled as a security control.\n\n### Fix Direction\nTreat `container.options` as untrusted input. Reject or strip when \nprivileged mode is disabled:\n\n- Host namespaces: `--pid=host`, `--ipc=host`, `--uts=host`, `--network=host`\n- Capability expansion: `--cap-add ALL`, `--cap-add SYS_ADMIN`\n- Security overrides: `--security-opt seccomp=unconfined`, `--security-opt apparmor=unconfined`\n- Device access: `--device`, `--device-cgroup-rule`\n- Volume inheritance: `--volumes-from`\n- Runtime controls: `--runtime`, `--cgroup-parent`",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "gitea.com/gitea/runner"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.9-0.20260731160927-34bfa1915022"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/go-gitea/gitea/security/advisories/GHSA-x4q3-gcj3-m6cf"
  }, {
    "type" : "WEB",
    "url" : "https://gitea.com/gitea/runner/pulls/1058"
  }, {
    "type" : "WEB",
    "url" : "https://gitea.com/gitea/runner/releases/tag/v3.0.0"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/go-gitea/gitea"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-269" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-02T23:18:12Z",
    "nvd_published_at" : null
  }
}