CVE-2026-43620 PUBLISHED

Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files()

Assigner: VulnCheck
Reserved: 01.05.2026 Published: 20.05.2026 Updated: 20.05.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 6.9

Product Status

Vendor RsyncProject
Product rsync
Versions Default: unaffected
  • affected from 0 to 3.4.3 (excl.)

Credits

  • Pratham Gupta (@prathamgupta36) finder

References

Problem Types

  • Out-of-bounds Read CWE