CVE-2026-73802.

Disclosure summary

### Summary act_runner appends workflow-controlled `jobs..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 con

Source-specific records & product guidance

Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.

Original records & references

• NIST NVD record
• CVE Program record
• github.com — Reviewed advisory

PUBLISHED 2026-10-02T19:18:12-04:00
MODIFIED 2026-10-02T19:18:13-04:00
INGESTED 2026-10-06T11:45:17-04:00