Skip to main content

rsync CVE-2026-70452

| EUVDEUVD-2026-58052 CRITICAL
Incorrect Authorization (CWE-863)
2026-08-13 VulnCheck
9.1
CVSS 4.0 · Vendor: VulnCheck
Share

Severity by source

Vendor (VulnCheck) PRIMARY
9.1 CRITICAL
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vuln.today AI
6.5 MEDIUM

Network-reachable and unauthenticated (AV:N/PR:N) but requires inducing a DNS failure (AC:H); high confidentiality from reading restricted modules, low integrity since only writable modules allow changes, no availability impact.

3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
SUSE
7.4 HIGH
AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Red Hat
7.4 HIGH
qualitative

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
X

Lifecycle Timeline

3
Source Code Evidence Fetched
Aug 13, 2026 - 15:46 vuln.today
Analysis Generated
Aug 13, 2026 - 15:46 vuln.today
CVE Published
Aug 13, 2026 - 14:46 cve.org
CRITICAL 9.1

DescriptionCVE.org

rsync 3.1.0 before 3.5.0 contains an access control bypass vulnerability that allows remote attackers to circumvent hosts deny rules by inducing DNS resolution failures during hostname-based access control evaluation. When a DNS lookup for a hostname-based deny rule fails, the daemon skips the rule rather than defaulting to a deny decision, enabling attackers who can trigger DNS failures to bypass module-level IP access controls and gain unauthorized access to restricted module file trees.

AnalysisAI

Access control bypass in rsync daemon versions 3.1.0 through 3.4.4 lets remote unauthenticated attackers evade module-level 'hosts deny' restrictions by forcing DNS resolution to fail during hostname-based access checks, causing the daemon to skip the rule (fail-open) instead of denying. Reported by VulnCheck and fixed in rsync 3.5.0, it exposes file trees in modules that were meant to be IP/hostname-restricted; no public exploit has been identified at time of analysis and it is not listed in CISA KEV.

Technical ContextAI

rsync's daemon mode enforces per-module access using 'hosts allow' / 'hosts deny' directives in rsyncd.conf, which can be specified as IP ranges or as hostnames. Hostname rules require the daemon to resolve the client's address via DNS at connection time. The flaw is a CWE-863 (Incorrect Authorization) issue: the evaluation logic treats a failed DNS lookup as 'rule not applicable' and proceeds, rather than failing closed to a deny decision. The affected component is the rsyncproject/rsync daemon (CPE cpe:2.3:a:rsyncproject:rsync), specifically the code path that maps a connecting IP back to a hostname for deny-rule matching.

RemediationAI

Vendor-released patch: rsync 3.5.0 - upgrade rsync to 3.5.0 or later (release: https://github.com/RsyncProject/rsync/releases/tag/v3.5.0, described by the vendor as a major security release). If immediate patching is not possible, replace hostname-based 'hosts deny'/'hosts allow' entries in rsyncd.conf with explicit numeric IP address/CIDR rules, which do not depend on DNS resolution and therefore cannot be bypassed via lookup failure (trade-off: harder to maintain for dynamic hosts). Additionally restrict the rsync daemon (default tcp/873) at a network firewall or bind it to trusted interfaces, and consider fronting it with SSH transport or a VPN so access control does not rely on the daemon's own hostname ACLs. Consult GHSA-6692-28cx-wpqq and the VulnCheck advisory for details.

More in Rsync

View all
CVE-2024-12085 HIGH POC
7.5 Jan 14

A flaw was found in rsync which could be triggered when rsync compares file checksums. Rated high severity (CVSS 7.5), t

CVE-2024-12084 CRITICAL POC
9.8 Jan 15

A heap-based buffer overflow flaw was found in the rsync daemon. Rated critical severity (CVSS 9.8), this vulnerability

CVE-2014-9512 MEDIUM POC
6.4 Feb 12

rsync 3.1.1 allows remote attackers to write to arbitrary files via a symlink attack on a file in the synchronization pa

CVE-2024-12087 HIGH POC
7.5 Jan 14

Server-to-client path traversal in rsync lets a malicious or compromised rsync server write files outside the client's i

CVE-2022-29154 HIGH POC
7.4 Aug 02

An issue was discovered in rsync before 3.2.5 that allows malicious remote servers to write arbitrary files inside the d

CVE-2014-2855 HIGH
7.8 Apr 23

The check_secret function in authenticate.c in rsync 3.1.0 and earlier allows remote attackers to cause a denial of serv

CVE-2024-12086 MEDIUM POC
6.8 Jan 14

A flaw was found in rsync. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authenticati

CVE-2017-16548 CRITICAL
9.8 Nov 06

The receive_xattr function in xattrs.c in rsync 3.1.2 and 3.1.3-development does not check for a trailing '\0' character

CVE-2017-17434 CRITICAL
9.8 Dec 06

The daemon in rsync 3.1.2, and 3.1.3-development before 2017-12-03, does not check for fnamecmp filenames in the daemon_

CVE-2017-15994 CRITICAL
9.8 Oct 29

rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to by

CVE-2026-53790 CRITICAL
9.2 Aug 13

Arbitrary command execution in rsync before 3.5.0 arises from multiple unsanitized code paths - the RSYNC_CONNECT_PROG e

CVE-2026-70460 CRITICAL
9.2 Aug 13

Arbitrary file write in rsync 2.3.3 through 3.4.4 lets a malicious sender escape a daemon module's root by abusing symli

Vendor StatusVendor

SUSE

Severity: Important
Product Status
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS Affected
SUSE Linux Enterprise Micro 5.3 Affected

Share

CVE-2026-70452 vulnerability details – vuln.today

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy