CVE-2026-70462
Received Received - Intake

Integer Overflow in Rsync Leading to Resource Exhaustion

Vulnerability report for CVE-2026-70462, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-13

Last updated on: 2026-08-13

Assigner: VulnCheck

Description

rsync 3.1.0 before 3.5.0 contains a signed integer overflow vulnerability in the I/O timeout implementation that allows attackers to permanently disable connection timeouts by injecting MSG_IO_TIMEOUT messages carrying non-positive (zero or negative) values. Attackers can craft malicious MSG_IO_TIMEOUT messages that cause the timeout variable to wrap to a non-positive value, preventing the timeout check from firing and enabling idle or stalled connections to hold daemon slots indefinitely, leading to resource exhaustion.

CVSS Scores

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Meta Information

Published
2026-08-13
Last Modified
2026-08-13
Generated
2026-08-13
AI Q&A
2026-08-13
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE
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KEV
KEV Icon
CWE ID Description
CWE-190 The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
CWE-835 The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.

Attack-Flow Graph

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Executive Summary

This vulnerability is a signed integer overflow in rsync versions 3.1.0 through 3.4.4. Attackers can send malicious MSG_IO_TIMEOUT messages with non-positive values (zero or negative), causing the timeout variable to wrap around. This prevents the timeout check from executing, allowing idle or stalled connections to hold daemon slots indefinitely and leading to resource exhaustion.

Detection Guidance

To detect this vulnerability, check the installed rsync version on your system using the command: rsync --version. If the version is between 3.1.0 and 3.4.4, the system is vulnerable. Additionally, monitor network traffic for unusual MSG_IO_TIMEOUT messages with non-positive values using packet inspection tools like Wireshark or tcpdump.

Impact Analysis

This vulnerability can allow attackers to permanently disable connection timeouts, causing resource exhaustion by holding daemon slots indefinitely. This may lead to denial of service, degraded performance, or system crashes due to unmanaged resource consumption.

Mitigation Strategies

Immediately upgrade rsync to version 3.5.0 or later. If upgrading is not possible, restrict network access to rsync services using firewalls or disable rsync daemon mode until patched. Monitor for signs of resource exhaustion or unusual connection behavior.

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