Detections
Analytics
Amazon Linux 2 : rsync (ALAS-2026-3945)
high Nessus Plugin ID 351084
Synopsis
The remote Amazon Linux 2 host is missing a security update.Description
The version of rsync installed on the remote host is prior to 3.1.2-11. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3945 advisory.rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.
NOTE: https://download.samba.org/pub/rsync/NEWS#3.5.0 (CVE-2026-70453)
rsync 3.0.0 before 3.5.0 contains an out-of-bounds write vulnerability that allows attackers to corrupt memory by triggering HLINK_BUMP processing on file entries with the FLAG_HLINKED flag set while the hard- link preservation option is inactive. Attackers can exploit the missing F_SUM field in the file_struct layout to access memory past the end of the allocated structure, corrupting adjacent heap or stack data.
NOTE: https://download.samba.org/pub/rsync/NEWS#3.5.0 (CVE-2026-70458)
Tenable has extracted the preceding description block directly from the tested product security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Run 'yum update rsync' or or 'yum update --advisory ALAS2-2026-3945' to update your system.See Also
https://alas.aws.amazon.com//AL2/ALAS2-2026-3945.html
https://alas.aws.amazon.com/faqs.html
Plugin Details
Severity: High
ID: 351084
File Name: al2_ALAS-2026-3945.nasl
Version: 1.1
Type: Local
Agent: unix
Published: 9/29/2026
Updated: 9/29/2026
Supported Sensors: Nessus Agent, Continuous Assessment, Nessus
Risk Information
VPR
Risk Factor: Low
Score: 3.5
Percentile: 51.68
CVSS v2
Risk Factor: High
Base Score: 8.5
Temporal Score: 6.3
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:C
CVSS Score Source: CVE-2026-70458
CVSS v3
Risk Factor: High
Base Score: 8.2
Temporal Score: 7.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C
CVSS v4
Risk Factor: High
Base Score: 8.8
Threat Score: 6.7
Threat Vector: CVSS:4.0/E:U
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
Vulnerability Information
CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:rsync-debuginfo, p-cpe:/a:amazon:linux:rsync
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 9/28/2026
Vulnerability Publication Date: 8/13/2026
Reference Information
CVE: CVE-2026-70453, CVE-2026-70458
IAVA: 2026-A-0906