CVE-2026-53794
rsync < 3.5.0 Denial of Service via --max-alloc=0 Logic Error
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.
INFO
Published Date :
Aug. 13, 2026, 3:19 p.m.
Last Modified :
Nov. 6, 2026, 4 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 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update rsync to version 3.5.0 or later.
- Ensure --max-alloc is set appropriately.
- Restart the rsync service.
- Monitor system memory usage.
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-2026-53794.
| URL | Resource |
|---|---|
| https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 | Release Notes |
| https://github.com/RsyncProject/rsync/security/advisories/GHSA-p827-vwcp-m964 | Vendor Advisory |
| https://www.vulncheck.com/advisories/rsync-denial-of-service-via-max-alloc-0-logic-error | 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-2026-53794 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-2026-53794
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-2026-53794 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53794 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]
Nov. 06, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:* versions up to (excluding) 3.5.0 Added Reference Type VulnCheck: https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 Types: Release Notes Added Reference Type VulnCheck: https://github.com/RsyncProject/rsync/security/advisories/GHSA-p827-vwcp-m964 Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/rsync-denial-of-service-via-max-alloc-0-logic-error Types: Third Party Advisory -
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Changed Translation Title: rsync de RsyncProject, Description: rsync anterior a la versión 3.5.0 contiene un error lógico en el manejo de --max-alloc que permite que un remitente o una configuración que establece --max-alloc=0 desactive por completo las comprobaciones de cordura de asignación en lugar de imponer un límite de cero bytes. Los atacantes pueden explotar esta falla para hacer que el receptor intente asignaciones de memoria ilimitadas para la lista de archivos y las estructuras de datos, agotando potencialmente la memoria disponible y causando una denegación de servicio. Title: rsync de RsyncProject, Description: rsync anterior a la versión 3.5.0 contiene un error lógico en el manejo de --max-alloc que permite que un remitente o una configuración que establece --max-alloc=0 desactive por completo las comprobaciones de cordura de asignación en lugar de imponer un límite de cero bytes. Los atacantes pueden explotar esta falla para hacer que el receptor intente asignaciones de memoria ilimitadas para la lista de archivos y las estructuras de datos, agotando potencialmente la memoria disponible y causando una denegación de servicio. -
CVE Translated by [email protected]
Oct. 23, 2026
Action Type Old Value New Value Added Translation Title: rsync de RsyncProject, Description: rsync anterior a la versión 3.5.0 contiene un error lógico en el manejo de --max-alloc que permite que un remitente o una configuración que establece --max-alloc=0 desactive por completo las comprobaciones de cordura de asignación en lugar de imponer un límite de cero bytes. Los atacantes pueden explotar esta falla para hacer que el receptor intente asignaciones de memoria ilimitadas para la lista de archivos y las estructuras de datos, agotando potencialmente la memoria disponible y causando una denegación de servicio. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 13, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-53794', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-13T15:34:23.072313Z'} -
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': '0', 'versionType': 'semver', 'lessThanOrEqual': '3.4.4'}, {'status': 'unaffected', 'version': '3.5.0', 'versionType': 'semver'}], 'packageURL': 'pkg:github/RsyncProject/rsync', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CWE CWE-1284 Added Reference https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 Added Reference https://github.com/RsyncProject/rsync/security/advisories/GHSA-p827-vwcp-m964 Added Reference https://www.vulncheck.com/advisories/rsync-denial-of-service-via-max-alloc-0-logic-error