CVE-2026-70453: CWE-407 Inefficient Algorithmic Complexity in RsyncProject rsync
rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.
AI Analysis
Technical Summary
The vulnerability in rsync before version 3.5.0 is due to an algorithmic complexity flaw (CWE-407) in the hash_search() function. A remote attacker can exploit this by delivering a carefully constructed file list that causes the hash lookup process to exhibit quadratic-time worst-case behavior. This leads to excessive CPU consumption on the receiver, effectively causing a denial of service condition. The issue affects all rsync versions up to and including 3.4.4.
Potential Impact
An unauthenticated remote attacker can cause a denial of service on the rsync receiver by exhausting CPU resources through crafted file lists. This disrupts normal operation and availability of the rsync service. There is no indication of data compromise or code execution from this vulnerability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider limiting exposure of rsync services to untrusted networks or implementing rate limiting to mitigate potential denial of service attempts.
CVE-2026-70453: CWE-407 Inefficient Algorithmic Complexity in RsyncProject rsync
Description
rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.
CVSS v4.0
Score 8.7high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in rsync before version 3.5.0 is due to an algorithmic complexity flaw (CWE-407) in the hash_search() function. A remote attacker can exploit this by delivering a carefully constructed file list that causes the hash lookup process to exhibit quadratic-time worst-case behavior. This leads to excessive CPU consumption on the receiver, effectively causing a denial of service condition. The issue affects all rsync versions up to and including 3.4.4.
Potential Impact
An unauthenticated remote attacker can cause a denial of service on the rsync receiver by exhausting CPU resources through crafted file lists. This disrupts normal operation and availability of the rsync service. There is no indication of data compromise or code execution from this vulnerability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, consider limiting exposure of rsync services to untrusted networks or implementing rate limiting to mitigate potential denial of service attempts.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-04T14:52:23.814Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7ddec8bf8831d5395d0019
Added to database: 08/13/2026, 15:12:08 UTC
Last enriched: 08/13/2026, 15:29:47 UTC
Last updated: 08/13/2026, 17:57:34 UTC
Views: 3
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