# CVE-2026-53794: rsync < 3.5.0 Denial of Service via --max-alloc=0 Logic Error

CVE-2026-53794 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-2026-53794
- Priority: Routine
- CVSS: 5.3 (Moderate)
- EPSS: 0.0057
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 13, 2026
- Weakness: Improper Validation of Specified Quantity in Input
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-53794

## Description

rsync before 3.5.0 contains a logic error in --max-alloc handling that allows a sender or configuration setting --max-alloc=0 to disable allocation sanity checks entirely rather than enforcing a zero-byte cap. Attackers can exploit this flaw to cause the receiver to attempt unbounded memory allocations for file list and data structures, potentially exhausting available memory and causing a denial of service.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rsync Debian 13.5 (trixie) | 3.5.0+ds1-0+deb13u1 | [DEBIAN-CVE-2026-53794](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53794.md) | Aug 27, 2026 |
| Linux | rsync Debian 14 | 3.5.0+ds1-1 | [DEBIAN-CVE-2026-53794](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53794.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 |

---

Data as of 2026-11-08T19:12:23Z 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

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.