KB5120240: Windows 11 version 23H2 Security Update (August 2026)

critical Nessus Plugin ID 334608

Synopsis

The remote Windows host is affected by multiple vulnerabilities.

Description

The remote Windows host is missing security update 5120240. It is, therefore, affected by multiple vulnerabilities

- Use after free in Microsoft QUIC allows an unauthorized attacker to execute code over a network.
(CVE-2026-62815)

- Improper neutralization of special elements used in a command ('command injection') in Windows Active Directory allows an unauthorized attacker to execute code over a network. (CVE-2026-49179)

- Heap-based buffer overflow in Microsoft Local Security Authority Server (lsasrv) allows an authorized attacker to execute code over a network. (CVE-2026-62784)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Apply Security Update 5120240

See Also

https://support.microsoft.com/help/5120240

Plugin Details

Severity: Critical

ID: 334608

File Name: smb_nt_ms26_aug_5120240.nasl

Version: 1.1

Type: Local

Agent: windows

Published: 8/11/2026

Updated: 8/11/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

CVSS v2

Risk Factor: Critical

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-62815

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/o:microsoft:windows_11_23h2

Required KB Items: SMB/MS_Bulletin_Checks/Possible

Patch Publication Date: 8/11/2026

Vulnerability Publication Date: 8/11/2026

Reference Information

CVE: CVE-2026-49179, CVE-2026-50472, CVE-2026-54113, CVE-2026-54984, CVE-2026-56174, CVE-2026-59122, CVE-2026-59125, CVE-2026-59126, CVE-2026-59127, CVE-2026-59128, CVE-2026-59130, CVE-2026-59131, CVE-2026-59132, CVE-2026-59134, CVE-2026-59135, CVE-2026-59136, CVE-2026-59137, CVE-2026-59138, CVE-2026-61345, CVE-2026-61346, CVE-2026-61347, CVE-2026-61348, CVE-2026-61349, CVE-2026-61350, CVE-2026-61352, CVE-2026-61353, CVE-2026-61355, CVE-2026-61356, CVE-2026-61358, CVE-2026-61359, CVE-2026-61360, CVE-2026-61363, CVE-2026-61364, CVE-2026-61365, CVE-2026-61366, CVE-2026-61367, CVE-2026-61368, CVE-2026-61918, CVE-2026-61921, CVE-2026-61923, CVE-2026-61924, CVE-2026-61925, CVE-2026-61926, CVE-2026-61928, CVE-2026-61929, CVE-2026-61930, CVE-2026-61932, CVE-2026-61934, CVE-2026-61936, CVE-2026-61937, CVE-2026-61939, CVE-2026-62690, CVE-2026-62692, CVE-2026-62695, CVE-2026-62696, CVE-2026-62698, CVE-2026-62699, CVE-2026-62700, CVE-2026-62701, CVE-2026-62702, CVE-2026-62703, CVE-2026-62707, CVE-2026-62709, CVE-2026-62710, CVE-2026-62711, CVE-2026-62712, CVE-2026-62713, CVE-2026-62717, CVE-2026-62719, CVE-2026-62721, CVE-2026-62723, CVE-2026-62724, CVE-2026-62725, CVE-2026-62726, CVE-2026-62728, CVE-2026-62729, CVE-2026-62730, CVE-2026-62732, CVE-2026-62733, CVE-2026-62734, CVE-2026-62735, CVE-2026-62736, CVE-2026-62738, CVE-2026-62739, CVE-2026-62740, CVE-2026-62741, CVE-2026-62743, CVE-2026-62746, CVE-2026-62747, CVE-2026-62748, CVE-2026-62750, CVE-2026-62751, CVE-2026-62752, CVE-2026-62753, CVE-2026-62755, CVE-2026-62757, CVE-2026-62758, CVE-2026-62768, CVE-2026-62769, CVE-2026-62770, CVE-2026-62771, CVE-2026-62773, CVE-2026-62774, CVE-2026-62777, CVE-2026-62780, CVE-2026-62781, CVE-2026-62782, CVE-2026-62783, CVE-2026-62784, CVE-2026-62785, CVE-2026-62786, CVE-2026-62788, CVE-2026-62790, CVE-2026-62792, CVE-2026-62793, CVE-2026-62795, CVE-2026-62796, CVE-2026-62797, CVE-2026-62798, CVE-2026-62800, CVE-2026-62811, CVE-2026-62815, CVE-2026-62816, CVE-2026-62817, CVE-2026-62819, CVE-2026-62822, CVE-2026-62832, CVE-2026-62876, CVE-2026-62877, CVE-2026-62880, CVE-2026-62881, CVE-2026-62883, CVE-2026-62885, CVE-2026-62887, CVE-2026-62888, CVE-2026-62889, CVE-2026-62890, CVE-2026-62892, CVE-2026-62894, CVE-2026-62908, CVE-2026-65662, CVE-2026-65671, CVE-2026-65672, CVE-2026-65678, CVE-2026-65773, CVE-2026-65774, CVE-2026-65775, CVE-2026-65777, CVE-2026-65784, CVE-2026-65786, CVE-2026-65787, CVE-2026-65788, CVE-2026-65790, CVE-2026-65794, CVE-2026-65795, CVE-2026-65797, CVE-2026-65798, CVE-2026-65799, CVE-2026-65814, CVE-2026-66799, CVE-2026-6726, CVE-2026-6727, CVE-2026-68820, CVE-2026-70304, CVE-2026-70307, CVE-2026-70330, CVE-2026-70344, CVE-2026-70345, CVE-2026-70346, CVE-2026-70347

MSFT: MS26-5120240

MSKB: 5120240