CVE-2026-53783
rsync < 3.5.0 TOCTOU Race Condition Directory Escape via rrsync
Description
rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree.
INFO
Published Date :
Aug. 13, 2026, 3:19 p.m.
Last Modified :
Nov. 6, 2026, 4:02 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 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update rsync to a fixed version.
- Remove the rrsync wrapper if possible.
- Restrict rsync flags if not updating.
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-2026-53783.
| URL | Resource |
|---|---|
| https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 | Release Notes |
| https://github.com/RsyncProject/rsync/security/advisories/GHSA-9cgc-64g4-3gv5 | Vendor Advisory |
| https://www.vulncheck.com/advisories/rsync-toctou-race-condition-directory-escape-via-rrsync | 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-2026-53783 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-2026-53783
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-2026-53783 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53783 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-9cgc-64g4-3gv5 Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/rsync-toctou-race-condition-directory-escape-via-rrsync 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 una vulnerabilidad de condición de carrera de tiempo de verificación a tiempo de uso (TOCTOU) en el envoltorio de shell restringido rrsync que permite a clientes autenticados evadir las restricciones de directorio impuestas al sustituir un enlace simbólico por un componente de ruta después de la validación pero antes del procesamiento de la transferencia. Los atacantes pueden aprovechar adicionalmente opciones no restringidas como --copy-unsafe-links, -D y --log-file a través de rrsync para leer o escribir archivos fuera del subárbol de directorio permitido. Title: rsync de RsyncProject, Description: rsync anterior a la versión 3.5.0 contiene una vulnerabilidad de condición de carrera de tiempo de verificación a tiempo de uso (TOCTOU) en el envoltorio de shell restringido rrsync que permite a clientes autenticados evadir las restricciones de directorio impuestas al sustituir un enlace simbólico por un componente de ruta después de la validación pero antes del procesamiento de la transferencia. Los atacantes pueden aprovechar adicionalmente opciones no restringidas como --copy-unsafe-links, -D y --log-file a través de rrsync para leer o escribir archivos fuera del subárbol de directorio permitido. -
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 una vulnerabilidad de condición de carrera de tiempo de verificación a tiempo de uso (TOCTOU) en el envoltorio de shell restringido rrsync que permite a clientes autenticados evadir las restricciones de directorio impuestas al sustituir un enlace simbólico por un componente de ruta después de la validación pero antes del procesamiento de la transferencia. Los atacantes pueden aprovechar adicionalmente opciones no restringidas como --copy-unsafe-links, -D y --log-file a través de rrsync para leer o escribir archivos fuera del subárbol de directorio permitido. -
CVE Modified by [email protected]
Aug. 14, 2026
Action Type Old Value New Value Changed 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'}], 'defaultStatus': 'unaffected'}] [{'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'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 14, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-53783', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-14T15:41:11.374187Z'} -
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'}], 'defaultStatus': 'unaffected'}] Added Description rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/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:L/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-59 Added CWE CWE-88 Added Reference https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 Added Reference https://github.com/RsyncProject/rsync/security/advisories/GHSA-9cgc-64g4-3gv5 Added Reference https://www.vulncheck.com/advisories/rsync-toctou-race-condition-directory-escape-via-rrsync