# CVE-2026-53792: rsync < 3.5.0 Out-of-Bounds Read via Zero-Length Checksum Block

CVE-2026-53792 is fixed in 4 products on 1 platform, first by SUSE-SU-2026:3657-1, released August 20, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-53792
- Priority: Routine
- CVSS: 6.5 (Moderate)
- EPSS: 0.0035
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 13, 2026
- Weakness: Improper Validation of Array Index
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53792

## Description

rsync before 3.5.0 contains an out-of-bounds read vulnerability in the sender-side block matching logic that allows a malicious receiver to trigger memory access before the start of an allocated buffer by sending a crafted checksum block with a length of zero. Attackers can send a specially crafted checksum set containing a zero-length block to cause a negative offset calculation during delta computation, resulting in an out-of-bounds read of file data buffer memory on the sender side.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rsync Debian 13.5 (trixie) | 3.5.0+ds1-0+deb13u1 | [DEBIAN-CVE-2026-53792](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53792.md) | Aug 27, 2026 |
| Linux | rsync Debian 14 | 3.5.0+ds1-1 | [DEBIAN-CVE-2026-53792](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53792.md) | Aug 27, 2026 |
| Linux | rsync amzn 2023 | 3.5.1-1.amzn2023.0.1 | [ALAS2023-2026-3131](https://patchblox.com/security/data/fix/linux/alas2023-2026-3131.md) | Sep 28, 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 15.6 | 3.2.7-150600.3.24.1 | [SUSE-SU-2026:3657-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3657-1.md) | Aug 20, 2026 |
| Linux | rsync sles 15.7 | 3.2.7-150600.3.24.1 | [SUSE-SU-2026:3657-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3657-1.md) | Aug 20, 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 |
| Linux | rsync-daemon amzn 2023 | 3.5.1-1.amzn2023.0.1 | [ALAS2023-2026-3131](https://patchblox.com/security/data/fix/linux/alas2023-2026-3131.md) | Sep 28, 2026 |
| Linux | rsync-debuginfo amzn 2023 | 3.5.1-1.amzn2023.0.1 | [ALAS2023-2026-3131](https://patchblox.com/security/data/fix/linux/alas2023-2026-3131.md) | Sep 28, 2026 |
| Linux | rsync-debugsource amzn 2023 | 3.5.1-1.amzn2023.0.1 | [ALAS2023-2026-3131](https://patchblox.com/security/data/fix/linux/alas2023-2026-3131.md) | Sep 28, 2026 |

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Data as of 2026-11-09T07:25:28Z 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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