CVE-2026-70453: CWE-407 Inefficient Algorithmic Complexity in RsyncProject rsync
CVE-2026-70453 is a high-severity vulnerability in rsync versions up to 3.4.4. It involves an algorithmic complexity issue in the hash_search() function that allows a remote attacker to cause a denial of service by sending a specially crafted file list. This triggers quadratic-time hash lookups, exhausting CPU resources on the receiver side and causing sustained service disruption.
AI Analysis
Technical Summary
The vulnerability in rsync before version 3.5.0 is due to inefficient algorithmic complexity in the hash_search() function. A remote attacker can exploit the quadratic-time worst-case behavior in hash lookups by delivering a carefully constructed file list, leading to excessive CPU consumption on the receiver. This results in a denial of service condition. The CVSS 4.0 score is 8.7, indicating high severity, with network attack vector, no privileges or user interaction required, and high impact on availability.
Potential Impact
An unauthenticated remote attacker can cause a denial of service on the rsync receiver by exhausting CPU resources through a crafted file list exploiting the quadratic-time hash lookup behavior. This can lead to sustained service unavailability or degraded performance.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is indicated in the available data. Users should monitor vendor communications for updates and apply patches once available.
CVE-2026-70453: CWE-407 Inefficient Algorithmic Complexity in RsyncProject rsync
Description
CVE-2026-70453 is a high-severity vulnerability in rsync versions up to 3.4.4. It involves an algorithmic complexity issue in the hash_search() function that allows a remote attacker to cause a denial of service by sending a specially crafted file list. This triggers quadratic-time hash lookups, exhausting CPU resources on the receiver side and causing sustained service disruption.
CVSS v4.0
Score 8.7high
Affected software
RsyncProject
rsync
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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 inefficient algorithmic complexity in the hash_search() function. A remote attacker can exploit the quadratic-time worst-case behavior in hash lookups by delivering a carefully constructed file list, leading to excessive CPU consumption on the receiver. This results in a denial of service condition. The CVSS 4.0 score is 8.7, indicating high severity, with network attack vector, no privileges or user interaction required, and high impact on availability.
Potential Impact
An unauthenticated remote attacker can cause a denial of service on the rsync receiver by exhausting CPU resources through a crafted file list exploiting the quadratic-time hash lookup behavior. This can lead to sustained service unavailability or degraded performance.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is indicated in the available data. Users should monitor vendor communications for updates and apply patches once available.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-04T14:52:23.814Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a7ddec8bf8831d5395d0019
Added to database: 08/13/2026, 15:12:08 UTC
Last enriched: 08/21/2026, 13:41:07 UTC
Last updated: 09/28/2026, 13:47:47 UTC
Views: 48
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