# CVE-2026-31886: Dagu has a Path Traversal via `dagRunId` in Inline DAG Execution > Attackers can delete system temporary files via path traversal in Dagu, causing denial of service for concurrent runs or the entire system. - **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 13 Mar 2026 - **Updated:** 13 Mar 2026 - **Also known as:** GHSA-m4q3-457p-hh2x, GO-2026-4693 ## What is CVE-2026-31886? CVE-2026-31886 is a critical path traversal vulnerability in dagu-org dagu, published on 13 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description Dagu is a workflow engine with a built-in Web user interface. Prior to 2.2.4, 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// 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. This vulnerability is fixed in 2.2.4. Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) ## Which versions are affected by CVE-2026-31886? 3 open source packages ship an affected version, including github.com/dagu-org/dagu. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `github.com/dagu-org/dagu` | Go | All versions | None | | `github.com/dagu-org/dagu` | Go | All versions to 2.2.4 | None | | `github.com/dagu-org/dagu` | Go | All versions to 2.2.4 | None | Products: Dagu Dagu. ## How do I fix CVE-2026-31886? Upgrade to a fixed version. ## Is CVE-2026-31886 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31886 exists. ## Other vulnerabilities in dagu-org dagu - [CVE-2026-33344](https://insights.sbomify.com/CVE-2026-33344/): Dagu has an incomplete fix for CVE-2026-27598: path traversal via %2F-encoded slashes in locateDAG (high 8.1) - [CVE-2026-31882](https://insights.sbomify.com/CVE-2026-31882/): Dagu SSE Authentication Bypass in Basic Auth Mode (high 7.5) - [CVE-2026-27598](https://insights.sbomify.com/CVE-2026-27598/): Dagu: Path traversal in DAG creation allows arbitrary YAML file write outside DAGs directory (high 7.1) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-31886 and fix it if it is affected. What it is: CVE-2026-31886 is a critical path traversal vulnerability in dagu-org dagu, published on 13 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31886 exists. Affected packages and fixed versions: - github.com/dagu-org/dagu (Go): affected all versions; no fix listed - github.com/dagu-org/dagu (Go): affected all versions up to 2.2.4; no fix listed - github.com/dagu-org/dagu (Go): affected all versions up to 2.2.4; no fix listed Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-31886/ (Markdown: https://insights.sbomify.com/CVE-2026-31886/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31886 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31886 - OSV: https://osv.dev/vulnerability/CVE-2026-31886 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-31886/ Summaries are generated and may contain mistakes; the official description above is the record.