CVE-2021-28799

Signals

NVD · CVE-2026-64604 · In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode When updating CR8NVD · CVE-2026-64603 · In the Linux kernel, the following vulnerability has been resolved: platform/x86: intel-hid: Protect ACPI notify handler against recursion Since commit e2ffcda1NVD · CVE-2026-64602 · In the Linux kernel, the following vulnerability has been resolved: iio: adc: spear: Initialize completion before requesting IRQ In the report from Jaeyoung ChuNVD · CVE-2026-64601 · In the Linux kernel, the following vulnerability has been resolved: ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on eachCISA KEV · CVE-2026-63077 · 9.8 · JetBrains TeamCity Deserialization of Untrusted Data Vulnerability · Added 2026-08-05 · Due 2026-08-08CISA KEV · CVE-2026-18556 · 7.4 · N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability · Added 2026-08-04 · Due 2026-08-07NVD · CVE-2026-64604 · In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode When updating CR8NVD · CVE-2026-64603 · In the Linux kernel, the following vulnerability has been resolved: platform/x86: intel-hid: Protect ACPI notify handler against recursion Since commit e2ffcda1NVD · CVE-2026-64602 · In the Linux kernel, the following vulnerability has been resolved: iio: adc: spear: Initialize completion before requesting IRQ In the report from Jaeyoung ChuNVD · CVE-2026-64601 · In the Linux kernel, the following vulnerability has been resolved: ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on eachCISA KEV · CVE-2026-63077 · 9.8 · JetBrains TeamCity Deserialization of Untrusted Data Vulnerability · Added 2026-08-05 · Due 2026-08-08CISA KEV · CVE-2026-18556 · 7.4 · N-able N-central Authentication Bypass Using an Alternate Path or Channel Vulnerability · Added 2026-08-04 · Due 2026-08-07

CVE Database · CVE-2021-28799

CVE-2021-28799

· CRITICALAnalyzed

CVSS v3.1

10.0

EPSS

78.25%

Published

May 13, 2021

Modified

Nov 3, 2025

CISA Known Exploited Vulnerability

Added: 2022-03-31 · Due: 2022-04-21

Apply updates per vendor instructions.

Public PoC / Exploit (2)

All weaponized →

NucleiNuclei detection template TrickestTrickest PoC index

Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.

Description

An improper authorization vulnerability has been reported to affect QNAP NAS running HBS 3 (Hybrid Backup Sync. ) If exploited, the vulnerability allows remote attackers to log in to a device. This issue affects: QNAP Systems Inc. HBS 3 versions prior to v16.0.0415 on QTS 4.5.2; versions prior to v3.0.210412 on QTS 4.3.6; versions prior to v3.0.210411 on QTS 4.3.4; versions prior to v3.0.210411 on QTS 4.3.3; versions prior to v16.0.0419 on QuTS hero h4.5.1; versions prior to v16.0.0419 on QuTScloud c4.5.1~c4.5.4. This issue does not affect: QNAP Systems Inc. HBS 2 . QNAP Systems Inc. HBS 1.3 .

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses (CWE)

CWE-285

Affected Products (11)

qnap · hybrid_backup_sync (up to 16.0.0415)vulnerable

qnap · qts

qnap · hybrid_backup_sync (up to 3.0.210412)vulnerable

qnap · qts

qnap · hybrid_backup_sync (up to 3.0.210411)vulnerable

qnap · qts

qnap · hybrid_backup_sync (up to 16.0.0419)vulnerable