Bug 2521034

Summary: CVE-2026-70462 rsync-bpc: rsync: Denial of Service via signed integer overflow in I/O timeout [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Srikanth Balasubramanian <sbalasub>
Component: rsync-bpcAssignee: Richard Shaw <hobbes1069>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: epel10CC: akito5623, hobbes1069
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["aee8eaaf-5080-4969-bffc-63a90632d47b"]}
Fixed In Version: Doc Type: ---
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2515391    

Description Srikanth Balasubramanian 2026-08-21 15:46:58 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.
Comment 1 Akiyoshi Kurita 2026-10-12 14:24:16 UTC 
A public proof-of-concept and the upstream fix for CVE-2026-70462 are available in the official rsync GitHub repository.

**PoC / Regression Tests:**
- https://github.com/RsyncProject/rsync/blob/master/testsuite/msg-io-timeout-overflow_test.py
- https://github.com/RsyncProject/rsync/blob/master/testsuite/msg-io-timeout-zero_test.py

**Upstream Fix (rsync 3.5.0):**
- https://github.com/RsyncProject/rsync/blob/v3.5.0/io.c

**Security Advisory:**
- https://github.com/RsyncProject/rsync/security/advisories/GHSA-j9wh-5jmp-2m64

Could the EPEL maintainer please verify whether rsync-bpc is affected and backport the upstream fix if applicable?

Best regards,
Akiyoshi Kurita
Fedora / EPEL / AlmaLinux Contributor
Linux Kernel Developer