CVE-2026-70457
rsync 3.2.3 < 3.5.0 Out-of-Bounds Write via parse_size_arg()
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.
INFO
Published Date :
Aug. 13, 2026, 3:19 p.m.
Last Modified :
Aug. 31, 2026, 3:12 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update rsync to version 3.5.0 or later.
- Apply vendor patches for rsync.
- Recompile rsync if necessary.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-70457.
| URL | Resource |
|---|---|
| https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 | Product Release Notes |
| https://github.com/RsyncProject/rsync/security/advisories/GHSA-pg7g-xqmr-xpfh | Vendor Advisory |
| https://www.vulncheck.com/advisories/rsync-out-of-bounds-write-via-parse-size-arg | Release Notes Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-70457 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-70457
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-70457 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-70457 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 31, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H Added CPE Configuration OR *cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:* versions from (including) 3.2.3 up to (excluding) 3.5.0 Added Reference Type VulnCheck: https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 Types: Product, Release Notes Added Reference Type VulnCheck: https://github.com/RsyncProject/rsync/security/advisories/GHSA-pg7g-xqmr-xpfh Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/rsync-out-of-bounds-write-via-parse-size-arg Types: Release Notes, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 13, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-70457', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-13T17:32:36.324059Z'} -
New CVE Received by [email protected]
Aug. 13, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/RsyncProject/rsync', 'vendor': 'RsyncProject', 'product': 'rsync', 'versions': [{'status': 'affected', 'version': '3.2.3', 'versionType': 'semver', 'lessThanOrEqual': '3.4.4'}, {'status': 'unaffected', 'version': '3.5.0', 'versionType': 'semver'}], 'packageURL': 'pkg:github/RsyncProject/rsync', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H Added CWE CWE-787 Added CWE CWE-131 Added Reference https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 Added Reference https://github.com/RsyncProject/rsync/security/advisories/GHSA-pg7g-xqmr-xpfh Added Reference https://www.vulncheck.com/advisories/rsync-out-of-bounds-write-via-parse-size-arg