Dagu: Path traversal in DAG creation allows arbitrary YAML file write outside DAGs directory

Exploitation

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

CVSS 4.0

7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-27598: 0.65% estimated exploitation activity in the next 30 days; percentile 51.17 (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.

The CreateNewDAG API endpoint (POST /api/v1/dags) does not validate the DAG name before passing it to the file store. While RenameDAG calls core.ValidateDAGName() to reject names containing path separators (line 273 in dags.go), CreateNewDAG skips this validation entirely and passes user input directly to dagStore.Create(). In internal/persis/filedag/store.go, the generateFilePath function (line 493) checks if the name contains a path separator, and if so, resolves it via filepath.Abs(name) — completely ignoring the baseDir. This means a name like ../../tmp/pwned will write a file to /tmp/pwned.yaml instead of the DAGs directory. Affected code: internal/service/frontend/api/v1/dags.go line 120-170 — CreateNewDAG handler, no call to ValidateDAGName internal/persis/filedag/store.go line 493-498 — generateFilePath resolves absolute path when name contains separator internal/persis/filedag/store.go line 213 — Create calls generateFilePath and writes attacker-controlled YAML content to…

Published by the source

24 Feb 2026, 21:43 UTC

Last modified by the source

27 Feb 2026, 20:40 UTC

Source last checked

26 Oct 2026, 15:14 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6v48-fcq6-ff23

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# Patch Next advisory brief: CVE-2026-27598

Advisory: Dagu: Path traversal in DAG creation allows arbitrary YAML file write outside DAGs directory
IDs: CVE-2026-27598, GHSA-6v48-fcq6-ff23
Record: https://patchnext.com/advisories/cve-2026-27598 (revision 1, source checked 26 Oct 2026, 15:14 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
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 <= 1.16.7

## 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-6v48-fcq6-ff23 (GitHub-reviewed advisory GHSA-6v48-fcq6-ff23 lists affected ranges: Go github.com/dagu-org/dagu >=0 <=1.16.7)

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