# CVE-2026-44510: rsync: Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files

CVE-2026-44510 is fixed in rsync on 1 platform, first by DEBIAN-CVE-2026-44510, released July 21, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-44510
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: n/a
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 20, 2026

## Description

Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files. In versions prior to 3.4.3, the receiver-side out-of-bounds array read in rsync's recv_files() lets a malicious rsync server (or any peer acting in the sender role) deterministically crash any rsync client that pulls from it. The trigger is fully wire-protocol-level, requires no special options on the victim, and works for both rsync:// URLs and remote-shell pulls; since inc_recurse is the protocol-30+ default, any client doing a normal recursive pull against an attacker-controlled URL is exposed. A malicious server sets CF_INC_RECURSE, sends a flist whose first sorted entry is not the leading "." directory (causing parent_ndx to be set to -1), then sends a transfer record with ndx = 0 and an iflag omitting ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference the result in f_name(). The impact is crash-only: the out-of-bounds read lands in glibc mmap chunk metadata and dereferences to an unmapped low address, producing a SEGV that cannot be leveraged into an exploit (confirmed on glibc x86-64 Linux; non-glibc allocators not audited). This issue is fixed in version 3.4.3.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rsync Debian 14 | 3.4.3+ds1-1 | [DEBIAN-CVE-2026-44510](https://patchblox.com/security/data/fix/linux/debian-cve-2026-44510.md) | Jul 21, 2026 |
| Linux | rsync opensuse-leap 16.0 | 3.4.1-160000.6.1 | [OPENSUSE-SU-2026:21650-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21650-1.md) | Aug 26, 2026 |
| Linux | rsync sles 16.0 | 3.4.1-160000.6.1 | [SUSE-SU-2026:23323-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23323-1.md) | Aug 26, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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