CVE-2026-70458Network attack vector

Remote memory corruption via invalid hard-link flag

Published Aug 13, 2026 · Updated Aug 13, 2026

Out-of-bounds write in rsync 3.0.0 through 3.4.4 allows remote attackers to corrupt receiver memory via crafted file entries. The receiver accepts FLAG_HLINKED without negotiated hard-link preservation, so F_SUM addresses attacker-supplied bytes beyond the allocated file entry. Exploitation requires protocol-30 incremental recursion, a regular file, checksum mode, and no -H, and the write can corrupt adjacent memory or crash the receiver.

CVSS severity8.8
High
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in rsync 3.0.0 through 3.4.4 allows remote attackers to corrupt receiver memory via crafted file entries. The receiver accepts FLAG_HLINKED without negotiated hard-link preservation, so F_SUM addresses attacker-supplied bytes beyond the allocated file entry. Exploitation requires protocol-30 incremental recursion, a regular file, checksum mode, and no -H, and the write can corrupt adjacent memory or crash the receiver.

The record

CVE
CVE-2026-70458
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Rsync Project
Product
rsync
Classifications
CWE-787, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.0.0 <=3.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rsync Project · rsyncversion=3.0.0 <=3.4.4

Published CVSS scores

8.8VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
8.2GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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