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CVE-2026-70464· NVD / CVE Program· CNA VulnCheck

rsync 2.0.0 < 3.5.0 Connection Slot Exhaustion DoS via Handshake Stall

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.57% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: azl3 rsync 3.4.3-1 on Azure Linux 3.0 3.5.0-1.

Low priority for now. Upgrade to azl3 rsync 3.4.3-1 on Azure Linux 3.0 3.5.0-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

rsync daemon 2.0.0 before 3.5.0 contains a denial of service vulnerability that allows unauthenticated remote attackers to exhaust daemon connection slots by stalling the handshake process before or after module selection without triggering the I/O timeout. Attackers can open many simultaneous connections and trickle data at the minimum rate to avoid timeout, or stall entirely before module selection where no timeout applies, consuming all available connection slots and denying service to legitimate clients.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Aug 13, 2026
Updated
Sep 8, 2026
EPSS
0.5% · 46th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulnCheck
8.7
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-70464

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.

  • RsyncProject rsync

    • 3.5.0not affected
    • 2.0.0 and later · up to and including 3.4.4affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:8rsyncbefore 3.1.3-28.el8_103.1.3-28.el8_10
AlmaLinux:8rsync-daemonbefore 3.1.3-28.el8_103.1.3-28.el8_10
AlmaLinux:9rsyncbefore 3.2.7-1.el9_83.2.7-1.el9_8
AlmaLinux:9rsync-daemonbefore 3.2.7-1.el9_83.2.7-1.el9_8
AlmaLinux:9rsync-rrsyncbefore 3.2.7-1.el9_83.2.7-1.el9_8
Alpine:v3.21rsyncbefore 3.5.0-r03.5.0-r0
Debian:12rsyncfrom 0—
Debian:13rsyncbefore 3.5.0+ds1-0+deb13u13.5.0+ds1-0+deb13u1
Debian:14rsyncbefore 3.5.0+ds1-13.5.0+ds1-1
Red Hat:enterprise_linux:8::baseosrsyncbefore 0:3.1.3-28.el8_100:3.1.3-28.el8_10
Red Hat:enterprise_linux:8::baseosrsync-daemonbefore 0:3.1.3-28.el8_100:3.1.3-28.el8_10
Red Hat:enterprise_linux:8::baseosrsync-debuginfobefore 0:3.1.3-28.el8_100:3.1.3-28.el8_10
Red Hat:enterprise_linux:8::baseosrsync-debugsourcebefore 0:3.1.3-28.el8_100:3.1.3-28.el8_10
Red Hat:enterprise_linux:9::appstreamrsync-daemonbefore 0:3.2.7-1.el9_80:3.2.7-1.el9_8
Red Hat:enterprise_linux:9::appstreamrsync-rrsyncbefore 0:3.2.7-1.el9_80:3.2.7-1.el9_8
Red Hat:enterprise_linux:9::baseosrsyncbefore 0:3.2.7-1.el9_80:3.2.7-1.el9_8
Red Hat:enterprise_linux:9::baseosrsync-debuginfobefore 0:3.2.7-1.el9_80:3.2.7-1.el9_8
Red Hat:enterprise_linux:9::baseosrsync-debugsourcebefore 0:3.2.7-1.el9_80:3.2.7-1.el9_8
Rocky Linux:8rsyncbefore 0:3.1.3-28.el8_100:3.1.3-28.el8_10
Rocky Linux:9rsyncbefore 0:3.2.7-1.el9_80:3.2.7-1.el9_8

Same product

rsyncproject: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-70460rsync 2.3.3 < 3.5.0 Path Traversal via --partial-dir/--backup-dir Symlink
    36Monitor
  • CVE-2026-70452rsync 3.1.0 < 3.5.0 Access Control Bypass via DNS Resolution Failure
    36Monitor
  • CVE-2026-53793rsync < 3.5.0 Path Confinement Bypass via /./ Boundary Marker in Chroot Mode
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-70456Aug 13, 2026 · rsync 3.0.1 < 3.5.0 Heap Out-of-Bounds Write via read_args()
    35Monitor
  • ← EarlierCVE-2026-70458Aug 13, 2026 · rsync 3.0.0 < 3.5.0 Out-of-Bounds Write via FLAG_HLINKED Handling
    35Monitor
  • ← EarlierCVE-2026-70462Aug 13, 2026 · rsync 3.1.0 < 3.5.0 Signed Integer Overflow via MSG_IO_TIMEOUT
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
azl3 rsync 3.4.3-1 on Azure Linux 3.03.5.0-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:rsync3.2.7-1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:rsync-daemon3.2.7-1.el9_8 · AlmaLinux:9Package registry (OSV)
almalinux:rsync-rrsync3.2.7-1.el9_8 · AlmaLinux:9Package registry (OSV)
alpine:rsync3.5.0-r0 · Alpine:v3.21Package registry (OSV)
debian:rsync3.5.0+ds1-0+deb13u1 · Debian:13Package registry (OSV)
red hat:rsync0:3.2.7-1.el9_8 · Red Hat:enterprise_linux:9::baseosPackage registry (OSV)
red hat:rsync-daemon0:3.2.7-1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:rsync-debuginfo0:3.2.7-1.el9_8 · Red Hat:enterprise_linux:9::baseosPackage registry (OSV)
red hat:rsync-debugsource0:3.2.7-1.el9_8 · Red Hat:enterprise_linux:9::baseosPackage registry (OSV)
red hat:rsync-rrsync0:3.2.7-1.el9_8 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
rocky linux:rsync0:3.2.7-1.el9_8 · Rocky Linux:9Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-770 · Allocation of Resources Without Limits or Throttling

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records