Dagu: Path Traversal via dagRunId in Inline DAG Execution

Exploitation

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

CVSS

9.1 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H

EPSS

• CVE-2026-31886: 0.44% estimated exploitation activity in the next 30 days; percentile 38.15 (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.

1. Vulnerability Summary The dagRunId request field accepted by the inline DAG execution endpoints is passed directly into filepath.Join to construct a temporary directory path without any format validation. Go's filepath.Join resolves .. segments lexically, so a caller can supply a value such as ".." to redirect the computed directory outside the intended /tmp/<name/<id path. A deferred cleanup function that calls os.RemoveAll on that directory then runs unconditionally when the HTTP handler returns, deleting whatever directory the traversal resolved to. With dagRunId set to "..", the resolved directory is the system temporary directory (/tmp on Linux). On non-root deployments, os.RemoveAll("/tmp") removes all files in /tmp owned by the dagu process user, disrupting every concurrent dagu run that has live temp files. On root or Docker deployments, the call removes the entire contents of /tmp, causing a system-wide denial of service. 2. This Is Not a Duplicate of Existing Advisories…

Published by the source

13 Mar 2026, 15:40 UTC

Last modified by the source

16 Mar 2026, 16:36 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-m4q3-457p-hh2x

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# Patch Next advisory brief: CVE-2026-31886

Advisory: Dagu: Path Traversal via `dagRunId` in Inline DAG Execution
IDs: CVE-2026-31886, GHSA-m4q3-457p-hh2x
Record: https://patchnext.com/advisories/cve-2026-31886 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/dagu-org/dagu: affected <= 2.2.4

## Suggested inspection (read-only)
- Go github.com/dagu-org/dagu: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/dagu-org/dagu.
- 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-m4q3-457p-hh2x (GitHub-reviewed advisory GHSA-m4q3-457p-hh2x lists affected ranges: Go github.com/dagu-org/dagu >=0 <=2.2.4)

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