CVE-2026-43617
Description
Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.
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 | {"endIncluding":"3.4.2"} | |
References
- https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
- https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f
- https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution
- https://www.suse.com/security/cve/CVE-2026-43617.html
- https://security-tracker.debian.org/tracker/CVE-2026-43617
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43617
CWEs
CWE-289
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.