What’s Vulnerable › Vulnerabilities

CVE-2026-43620: Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files()

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-20 · updated 2026-07-24
• Weakness: CWE-125

Description

Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.

Affected products

• RsyncProject rsync: through 3.4.2

References

• https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
• https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm
• https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files

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