# CVE-2026-70457: rsync 3.2.3 < 3.5.0 Out-of-Bounds Write via parse_size_arg()

CVE-2026-70457 is fixed in 5 products on 1 platform, first by RHSA-2026:67463, released August 13, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-70457
- Priority: High
- CVSS: 8.2 (Moderate)
- EPSS: 0.0038
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 13, 2026
- Weakness: Incorrect Calculation of Buffer Size
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70457

## Description

rsync 3.2.3 before 3.5.0 contains an out-of-bounds write in parse_size_arg() where the return value of snprintf() is used directly as an index into a .bss-segment array without bounds checking. When snprintf truncates the formatted size string, the return value equals the number of characters that would have been written including the truncated portion, and this value may exceed the array length. The subsequent indexed write targets memory outside the intended array bounds, corrupting .bss memory.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | rsync Debian 13.5 (trixie) | 3.5.0+ds1-0+deb13u1 | [DEBIAN-CVE-2026-70457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-70457.md) | Aug 27, 2026 |
| Linux | rsync Debian 14 | 3.5.0+ds1-1 | [DEBIAN-CVE-2026-70457](https://patchblox.com/security/data/fix/linux/debian-cve-2026-70457.md) | Aug 27, 2026 |
| Linux | rsync RHEL 10 | 3.5.0-3.el10_2 | [RHSA-2026:67463](https://patchblox.com/security/data/fix/linux/rhsa-2026-67463.md) | Aug 13, 2026 |
| Linux | rsync RHEL 9 | 0:3.2.7-1.el9_8 | [RHSA-2026:67462](https://patchblox.com/security/data/fix/linux/rhsa-2026-67462.md) | Sep 19, 2026 |
| Linux | rsync almalinux 10 | 3.5.0-3.el10_2 | [ALSA-2026:67463](https://patchblox.com/security/data/fix/linux/alsa-2026-67463.md) | Sep 14, 2026 |
| Linux | rsync almalinux 9 | 3.2.7-1.el9_8 | [ALSA-2026:67462](https://patchblox.com/security/data/fix/linux/alsa-2026-67462.md) | Sep 14, 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 ol 10 | 0:3.5.0-3.el10_2 | [ELSA-2026-67463-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67463-0.md) | Sep 16, 2026 |
| Linux | rsync ol 9 | 0:3.2.7-1.el9_8 | [ELSA-2026-67462-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67462-0.md) | Sep 16, 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 rocky 10 | 0:3.5.0-3.el10_2 | [RLSA-2026:67463](https://patchblox.com/security/data/fix/linux/rlsa-2026-67463.md) | Sep 15, 2026 |
| Linux | rsync rocky 9 | 0:3.2.7-1.el9_8 | [RLSA-2026:67462](https://patchblox.com/security/data/fix/linux/rlsa-2026-67462.md) | Sep 15, 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 RHEL 9 | 0:3.2.7-1.el9_8 | [RHSA-2026:67462](https://patchblox.com/security/data/fix/linux/rhsa-2026-67462.md) | Sep 19, 2026 |
| Linux | rsync-daemon almalinux 10 | 3.5.0-3.el10_2 | [ALSA-2026:67463](https://patchblox.com/security/data/fix/linux/alsa-2026-67463.md) | Sep 14, 2026 |
| Linux | rsync-daemon almalinux 9 | 3.2.7-1.el9_8 | [ALSA-2026:67462](https://patchblox.com/security/data/fix/linux/alsa-2026-67462.md) | Sep 14, 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-daemon ol 10 | 0:3.5.0-3.el10_2 | [ELSA-2026-67463-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67463-0.md) | Sep 16, 2026 |
| Linux | rsync-daemon ol 9 | 0:3.2.7-1.el9_8 | [ELSA-2026-67462-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67462-0.md) | Sep 16, 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 |
| Linux | rsync-rrsync RHEL 9 | 0:3.2.7-1.el9_8 | [RHSA-2026:67462](https://patchblox.com/security/data/fix/linux/rhsa-2026-67462.md) | Sep 19, 2026 |
| Linux | rsync-rrsync almalinux 10 | 3.5.0-3.el10_2 | [ALSA-2026:67463](https://patchblox.com/security/data/fix/linux/alsa-2026-67463.md) | Sep 14, 2026 |
| Linux | rsync-rrsync almalinux 9 | 3.2.7-1.el9_8 | [ALSA-2026:67462](https://patchblox.com/security/data/fix/linux/alsa-2026-67462.md) | Sep 14, 2026 |
| Linux | rsync-rrsync ol 10 | 0:3.5.0-3.el10_2 | [ELSA-2026-67463-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67463-0.md) | Sep 16, 2026 |
| Linux | rsync-rrsync ol 9 | 0:3.2.7-1.el9_8 | [ELSA-2026-67462-0](https://patchblox.com/security/data/fix/linux/elsa-2026-67462-0.md) | Sep 16, 2026 |

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Data as of 2026-11-09T01:18:40Z 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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