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rsync EUVDEUVD-2026-58041

| CVE-2026-70463 HIGH
Incorrect Authorization (CWE-863)
2026-08-13 VulnCheck
8.6
CVSS 4.0 · Vendor: VulnCheck
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Severity by source

Vendor (VulnCheck) PRIMARY
8.6 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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
8.1 HIGH

Network-accessible rsync daemon requires authenticated user (PR:L); no scope change; no availability impact from authorization bypass alone.

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

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

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

Lifecycle Timeline

3
Source Code Evidence Fetched
Aug 13, 2026 - 15:40 vuln.today
Analysis Generated
Aug 13, 2026 - 15:40 vuln.today
CVE Published
Aug 13, 2026 - 14:42 cve.org
HIGH 8.6

DescriptionCVE.org

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.

AnalysisAI

Authorization bypass in rsync 3.1.0 through 3.4.x allows authenticated users to circumvent module-level access controls when group-based deny rules are configured with space-containing group names. The auth users directive's comma-only parser silently discards deny rules for any @Group Name entry whose group name contains a space, granting unintended access to restricted rsync modules regardless of the administrator's intended group-based exclusions. The rsync project designated v3.5.0 a major security release to address this flaw; no CISA KEV listing or public exploit code has been identified at time of analysis.

Technical ContextAI

rsync's daemon mode (rsyncd) supports per-module access controls via the auth users directive in rsyncd.conf, which accepts usernames and @groupname tokens with optional allow/deny semantics. CVE-2026-70463 (CWE-863: Incorrect Authorization) originates in the user-list tokenizer, which splits entries exclusively on commas without accounting for multi-word tokens. When an administrator writes a rule such as auth users = @Domain Admins, the parser splits the token at the space boundary, interpreting @Domain and Admins as two separate, malformed entries and silently dropping the deny rule that was intended for the group. The affected CPE is cpe:2.3:a:rsyncproject:rsync:*:*:*:*:*:*:*:* spanning versions 3.1.0 up to but not including 3.5.0. The root cause is a parsing invariant violation - the tokenizer assumes no valid token contains whitespace - rather than a cryptographic or memory-safety failure.

RemediationAI

Vendor-released patch: v3.5.0. Upgrade rsync to version 3.5.0, designated by the rsync project as a major security release, available at https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 with advisory details at https://github.com/RsyncProject/rsync/security/advisories/GHSA-pfj8-79vq-xgvr. Until patching is feasible, audit all rsyncd.conf auth users directives for @Group Name entries whose group names contain spaces; renaming OS groups to eliminate spaces (e.g., replacing Domain Admins with DomainAdmins) and updating the directive accordingly prevents the parser from mishandling the entry - note this requires coordinated updates to any other services relying on those OS group names. As an additional compensating control, restrict rsync daemon network exposure via host-based firewall rules or the hosts allow directive in rsyncd.conf to limit the population of hosts that can authenticate, reducing the attack surface. Restricting network access does not eliminate the vulnerability but meaningfully limits who can reach the affected parsing logic.

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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

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EUVD-2026-58041 vulnerability details – vuln.today

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