CVE-2026-53788Network attack vectorHinoki check available

Remote mapping corruption via newline request injection

Published Aug 13, 2026 · Updated Aug 13, 2026

Injection in rsync before 3.5.0 allows remote attackers to forge name-converter protocol requests with newline-bearing user or group names. The daemon writes peer-controlled names verbatim into the helper's persistent line protocol, so embedded CR or LF characters become injected requests. Exposure requires a daemon module configured with a name converter; forged requests can corrupt user and group identity mappings.

CVSS severity6.9
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Injection in rsync before 3.5.0 allows remote attackers to forge name-converter protocol requests with newline-bearing user or group names. The daemon writes peer-controlled names verbatim into the helper's persistent line protocol, so embedded CR or LF characters become injected requests. Exposure requires a daemon module configured with a name converter; forged requests can corrupt user and group identity mappings.

The record

CVE
CVE-2026-53788
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Rsync Project
Product
rsync
Classifications
CWE-74, CWE-93, T1190
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=0 <=3.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rsync Project · rsyncversion=0 <=3.4.4

Published CVSS scores

6.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
6.5RsyncProjectCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
T1190Exploit Public-Facing Application

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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