CVE-2026-53794Network attack vector

Denial of service via disabled allocation cap

Published Aug 13, 2026 · Updated Aug 13, 2026

Resource exhaustion in --max-alloc handling in rsync 3.4.4 and earlier allows remote attackers to interrupt transfers via a zero value. The option parser and daemon-side forwarded-option handler treat --max-alloc=0 as disabling the per-allocation sanity check instead of rejecting zero. Any peer that can initiate a transfer can remove the cap, allowing oversized protocol-driven allocations to exhaust memory and terminate the affected process.

CVSS severity5.3
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in --max-alloc handling in rsync 3.4.4 and earlier allows remote attackers to interrupt transfers via a zero value. The option parser and daemon-side forwarded-option handler treat --max-alloc=0 as disabling the per-allocation sanity check instead of rejecting zero. Any peer that can initiate a transfer can remove the cap, allowing oversized protocol-driven allocations to exhaust memory and terminate the affected process.

The record

CVE
CVE-2026-53794
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Rsync Project
Product
rsync
Classifications
T1499.004
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

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

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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