Vulnerability · Published Aug 13, 2026 · Assigned by VulnCheck
CVE-2026-70463rsync 3.1.0 < 3.5.0 Authorization Bypass via auth users Directive Parsing
High 8.1
In plain English
A high-severity incorrect authorization in rsync from RsyncProject. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
rsync 3.1.0 before 3.5.0 contains an authorization bypass in auth users directive parsing. The auth users parser uses comma-only tokenization when splitting the user list, which fails to correctly handle entries of the form @Group Name where the group name contains a space. The space within the group name causes the parser to split the entry at the space boundary, discarding the deny rule associated with the group. An authenticated user whose username or group membership would be denied by an @Group Name auth users entry can connect to a restricted module because the deny rule is silently discarded during parsing.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | rsync | 3.5.0-3.el10_2 | ALSA-2026:67463 |
| AlmaLinux:8 | rsync | 3.1.3-28.el8_10 | ALSA-2026:74095 |
| AlmaLinux:9 | rsync | 3.2.7-1.el9_8 | ALSA-2026:67462 |
| AlmaLinux:10 | rsync-daemon | 3.5.0-3.el10_2 | ALSA-2026:67463 |
| AlmaLinux:8 | rsync-daemon | 3.1.3-28.el8_10 | ALSA-2026:74095 |
| AlmaLinux:9 | rsync-daemon | 3.2.7-1.el9_8 | ALSA-2026:67462 |
| AlmaLinux:10 | rsync-rrsync | 3.5.0-3.el10_2 | ALSA-2026:67463 |
| AlmaLinux:9 | rsync-rrsync | 3.2.7-1.el9_8 | ALSA-2026:67462 |
| Alpine:v3.21 | rsync | 3.5.0-r0 | ALPINE-CVE-2026-70463 |
| Alpine:v3.22 | rsync | 3.5.0-r0 | ALPINE-CVE-2026-70463 |
| Alpine:v3.23 | rsync | 3.5.0-r0 | ALPINE-CVE-2026-70463 |
| Alpine:v3.24 | rsync | 3.5.0-r0 | ALPINE-CVE-2026-70463 |
| Debian:12 | rsync | no fix listed | DEBIAN-CVE-2026-70463 |
| Debian:13 | rsync | 3.5.0+ds1-0+deb13u1 | DEBIAN-CVE-2026-70463 |
| Debian:14 | rsync | 3.5.0+ds1-1 | DEBIAN-CVE-2026-70463 |
| Rocky Linux:10 | rsync | 0:3.5.0-3.el10_2 | RLSA-2026:67463 |
| Rocky Linux:8 | rsync | 0:3.1.3-28.el8_10 | RLSA-2026:74095 |
| Rocky Linux:9 | rsync | 0:3.2.7-1.el9_8 | RLSA-2026:67462 |
| Ubuntu:22.04:LTS | rsync | no fix listed | UBUNTU-CVE-2026-70463 |
| Ubuntu:24.04:LTS | rsync | no fix listed | UBUNTU-CVE-2026-70463 |
| Ubuntu:26.04:LTS | rsync | no fix listed | UBUNTU-CVE-2026-70463 |
| Ubuntu:26.10 | rsync | no fix listed | UBUNTU-CVE-2026-70463 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| RsyncProject | rsync | 3.1.0 – through 3.4.4 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References
- GitHub Security Advisory (GHSA-pfj8-79vq-xgvr) vendor-advisory
- rsync 3.5.0 Release Notes release-notes
- https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-auth-users-directive-parsing third-party-advisory