CVE-2026-29518
Description
Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with symbolic links. Attackers with write access to a module path can exploit this race condition to create or overwrite arbitrary files, potentially modifying sensitive system files and achieving privilege escalation when the daemon runs with elevated privileges. This vulnerability can only be triggered if the chroot setting is false.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 3.2.7-1+deb12u5 |
| debian | bullseye | fixed | 3.2.3-4+deb11u4 |
| debian | forky | fixed | 3.4.3+ds1-1 |
| debian | sid | fixed | 3.4.3+ds1-1 |
| debian | trixie | fixed | 3.4.1+ds1-5+deb13u3 |
| windows | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| samba | rsync | {"endExcluding":"3.4.3"} | 3.4.3 |
References
- https://github.com/RsyncProject/rsync/pull/895/changes/8471fdd1561049ef5f58df44a1811a50bd9a531d
- https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
- https://michael.stapelberg.ch/posts/2026-05-24-minimal-memory-safe-go-rsync-vulns/
- https://www.vulncheck.com/advisories/rsync-toctou-race-condition-allows-symlink-based-arbitrary-file-write
- https://www.suse.com/security/cve/CVE-2026-29518.html
- https://security-tracker.debian.org/tracker/CVE-2026-29518
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-29518
CWEs
CWE-367
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.