CVE-2026-41539 | QTS, QuTS hero

A cross-site scripting (XSS) vulnerability has been reported to affect several QNAP operating system versions. The remote attackers can then exploit the vulnerability to bypass security mechanisms or read application data. We have already fixed the vulnerability in the following versions: QTS 5.2.9.3492 build 20260507 and later QuTS hero h5.2.9.3499 build 20260514 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3500 build 20260520 and later

Published: 2026-06-09 Last update: 2026-06-12 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-41539 is rated Low Risk (38.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.19%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-41539

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.09% 0.19% +0.10%
2 2026-06-09 0.09%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-41539

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.7 4.0 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/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 Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:N)
No additional preconditions are required beyond normal reachability.
Privileges required (PR:N)
No privileges are required.
User interaction (UI:P)
A user has to participate (for example click/open/approve).
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:H)
High integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:H)
High availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.
Exploit maturity (threat) (E:X)
Not defined: no reliable threat intelligence; scoring assumes the worst case (equivalent to Attacked).
Confidentiality requirement (CR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Integrity requirement (IR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Availability requirement (AR:X)
Not defined: insufficient information; scoring treats this like High (worst case).
Modified attack vector (MAV:X)
Not defined: scoring uses the Base Attack Vector (AV).
Modified attack complexity (MAC:X)
Not defined: scoring uses the Base Attack Complexity (AC).
Modified attack requirements (MAT:X)
Not defined: scoring uses the Base Attack Requirements (AT).
Modified privileges required (MPR:X)
Not defined: scoring uses the Base Privileges Required (PR).
Modified user interaction (MUI:X)
Not defined: scoring uses the Base User Interaction (UI).
Modified vulnerable system confidentiality impact (MVC:X)
Not defined: scoring uses the Base VC metric.
Modified vulnerable system integrity impact (MVI:X)
Not defined: scoring uses the Base VI metric.
Modified vulnerable system availability impact (MVA:X)
Not defined: scoring uses the Base VA metric.
Modified subsequent system confidentiality impact (MSC:X)
Not defined: scoring uses the Base SC metric.
Modified subsequent system integrity impact (MSI:X)
Not defined: scoring uses the Base SI metric.
Modified subsequent system availability impact (MSA:X)
Not defined: scoring uses the Base SA metric.
Safety (supplemental) (S:X)
Not evaluated.
Automatable (supplemental) (AU:X)
Not evaluated.
Recovery (supplemental) (R:X)
Not evaluated.
Value density (supplemental) (V:X)
Not evaluated.
Vulnerability response effort (supplemental) (RE:X)
Not evaluated.
Provider urgency (supplemental) (U:X)
Not evaluated.
[email protected]
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 2.7 [email protected]

Weakness enumeration for CVE-2026-41539

GitHub Security Advisory for CVE-2026-41539

GHSA-hc5c-8r54-29r3 · Severity: high — A cross-site scripting (XSS) vulnerability has been reported to affect several QNAP operating...

Affected software / configurations for CVE-2026-41539

Vendor Product Version Raw CPE
qnap qts 5.2.0.2737 cpe:2.3:o:qnap:qts:5.2.0.2737:build_20240417:*:*:*:*:*:*
qnap qts 5.2.0.2744 cpe:2.3:o:qnap:qts:5.2.0.2744:build_20240424:*:*:*:*:*:*
qnap qts 5.2.0.2782 cpe:2.3:o:qnap:qts:5.2.0.2782:build_20240601:*:*:*:*:*:*
qnap qts 5.2.0.2802 cpe:2.3:o:qnap:qts:5.2.0.2802:build_20240620:*:*:*:*:*:*
qnap qts 5.2.0.2823 cpe:2.3:o:qnap:qts:5.2.0.2823:build_20240711:*:*:*:*:*:*
qnap qts 5.2.0.2851 cpe:2.3:o:qnap:qts:5.2.0.2851:build_20240808:*:*:*:*:*:*
qnap qts 5.2.0.2860 cpe:2.3:o:qnap:qts:5.2.0.2860:build_20240817:*:*:*:*:*:*
qnap qts 5.2.1.2930 cpe:2.3:o:qnap:qts:5.2.1.2930:build_20241025:*:*:*:*:*:*
qnap qts 5.2.2.2950 cpe:2.3:o:qnap:qts:5.2.2.2950:build_20241114:*:*:*:*:*:*
qnap qts 5.2.3.3006 cpe:2.3:o:qnap:qts:5.2.3.3006:build_20250108:*:*:*:*:*:*
qnap qts 5.2.4.3070 cpe:2.3:o:qnap:qts:5.2.4.3070:build_20250312:*:*:*:*:*:*
qnap qts 5.2.4.3079 cpe:2.3:o:qnap:qts:5.2.4.3079:build_20250321:*:*:*:*:*:*
qnap qts 5.2.4.3092 cpe:2.3:o:qnap:qts:5.2.4.3092:build_20250403:*:*:*:*:*:*
qnap qts 5.2.5.3145 cpe:2.3:o:qnap:qts:5.2.5.3145:build_20250526:*:*:*:*:*:*
qnap qts 5.2.6.3195 cpe:2.3:o:qnap:qts:5.2.6.3195:build_20250715:*:*:*:*:*:*
qnap qts 5.2.6.3229 cpe:2.3:o:qnap:qts:5.2.6.3229:build_20250818:*:*:*:*:*:*
qnap qts 5.2.7.3256 cpe:2.3:o:qnap:qts:5.2.7.3256:build_20250913:*:*:*:*:*:*
qnap qts 5.2.7.3297 cpe:2.3:o:qnap:qts:5.2.7.3297:build_20251024:*:*:*:*:*:*
qnap qts 5.2.8.3332 cpe:2.3:o:qnap:qts:5.2.8.3332:build_20251128:*:*:*:*:*:*
qnap qts 5.2.8.3350 cpe:2.3:o:qnap:qts:5.2.8.3350:build_20251216:*:*:*:*:*:*
qnap qts 5.2.8.3359 cpe:2.3:o:qnap:qts:5.2.8.3359:build_20251225:*:*:*:*:*:*
qnap qts 5.2.9.3410 cpe:2.3:o:qnap:qts:5.2.9.3410:build_20260214:*:*:*:*:*:*
qnap qts 5.2.9.3451 cpe:2.3:o:qnap:qts:5.2.9.3451:build_20260327:*:*:*:*:*:*
qnap quts_hero h5.2.0.2737 cpe:2.3:o:qnap:quts_hero:h5.2.0.2737:build_20240417:*:*:*:*:*:*
qnap quts_hero h5.2.0.2782 cpe:2.3:o:qnap:quts_hero:h5.2.0.2782:build_20240601:*:*:*:*:*:*
qnap quts_hero h5.2.0.2789 cpe:2.3:o:qnap:quts_hero:h5.2.0.2789:build_20240607:*:*:*:*:*:*
qnap quts_hero h5.2.0.2802 cpe:2.3:o:qnap:quts_hero:h5.2.0.2802:build_20240620:*:*:*:*:*:*
qnap quts_hero h5.2.0.2823 cpe:2.3:o:qnap:quts_hero:h5.2.0.2823:build_20240711:*:*:*:*:*:*
qnap quts_hero h5.2.0.2851 cpe:2.3:o:qnap:quts_hero:h5.2.0.2851:build_20240808:*:*:*:*:*:*
qnap quts_hero h5.2.0.2860 cpe:2.3:o:qnap:quts_hero:h5.2.0.2860:build_20240817:*:*:*:*:*:*
qnap quts_hero h5.2.1.2929 cpe:2.3:o:qnap:quts_hero:h5.2.1.2929:build_20241025:*:*:*:*:*:*
qnap quts_hero h5.2.1.2940 cpe:2.3:o:qnap:quts_hero:h5.2.1.2940:build_20241105:*:*:*:*:*:*
qnap quts_hero h5.2.2.2952 cpe:2.3:o:qnap:quts_hero:h5.2.2.2952:build_20241116:*:*:*:*:*:*
qnap quts_hero h5.2.3.3006 cpe:2.3:o:qnap:quts_hero:h5.2.3.3006:build_20250108:*:*:*:*:*:*
qnap quts_hero h5.2.4.3070 cpe:2.3:o:qnap:quts_hero:h5.2.4.3070:build_20250312:*:*:*:*:*:*
qnap quts_hero h5.2.4.3079 cpe:2.3:o:qnap:quts_hero:h5.2.4.3079:build_20250321:*:*:*:*:*:*
qnap quts_hero h5.2.5.3138 cpe:2.3:o:qnap:quts_hero:h5.2.5.3138:build_20250519:*:*:*:*:*:*
qnap quts_hero h5.2.6.3195 cpe:2.3:o:qnap:quts_hero:h5.2.6.3195:build_20250715:*:*:*:*:*:*
qnap quts_hero h5.2.7.3256 cpe:2.3:o:qnap:quts_hero:h5.2.7.3256:build_20250913:*:*:*:*:*:*
qnap quts_hero h5.2.7.3297 cpe:2.3:o:qnap:quts_hero:h5.2.7.3297:build_20251024:*:*:*:*:*:*
qnap quts_hero h5.2.8.3321 cpe:2.3:o:qnap:quts_hero:h5.2.8.3321:build_20251117:*:*:*:*:*:*
qnap quts_hero h5.2.8.3350 cpe:2.3:o:qnap:quts_hero:h5.2.8.3350:build_20251216:*:*:*:*:*:*
qnap quts_hero h5.2.8.3359 cpe:2.3:o:qnap:quts_hero:h5.2.8.3359:build_20251225:*:*:*:*:*:*
qnap quts_hero h5.2.9.3410 cpe:2.3:o:qnap:quts_hero:h5.2.9.3410:build_20260214:*:*:*:*:*:*
qnap quts_hero h5.2.9.3492 cpe:2.3:o:qnap:quts_hero:h5.2.9.3492:build_20260507:*:*:*:*:*:*
qnap quts_hero h5.3.0.3115 cpe:2.3:o:qnap:quts_hero:h5.3.0.3115:build_20250430:*:*:*:*:*:*
qnap quts_hero h5.3.0.3145 cpe:2.3:o:qnap:quts_hero:h5.3.0.3145:build_20250530:*:*:*:*:*:*
qnap quts_hero h5.3.0.3192 cpe:2.3:o:qnap:quts_hero:h5.3.0.3192:build_20250716:*:*:*:*:*:*
qnap quts_hero h5.3.1.3250 cpe:2.3:o:qnap:quts_hero:h5.3.1.3250:build_20250912:*:*:*:*:*:*
qnap quts_hero h5.3.1.3292 cpe:2.3:o:qnap:quts_hero:h5.3.1.3292:build_20251024:*:*:*:*:*:*
qnap quts_hero h5.3.2.3354 cpe:2.3:o:qnap:quts_hero:h5.3.2.3354:build_20251225:*:*:*:*:*:*
qnap quts_hero h5.3.3.3424 cpe:2.3:o:qnap:quts_hero:h5.3.3.3424:build_20260305:*:*:*:*:*:*
qnap quts_hero h6.0.0.3324 cpe:2.3:o:qnap:quts_hero:h6.0.0.3324:build_20251125:*:*:*:*:*:*
qnap quts_hero h6.0.0.3382 cpe:2.3:o:qnap:quts_hero:h6.0.0.3382:build_20260122:*:*:*:*:*:*
qnap quts_hero h6.0.0.3397 cpe:2.3:o:qnap:quts_hero:h6.0.0.3397:build_20260206:*:*:*:*:*:*
qnap quts_hero h6.0.0.3459 cpe:2.3:o:qnap:quts_hero:h6.0.0.3459:build_20260409:*:*:*:*:*:*

References for CVE-2026-41539

cvelogic Threat Intelligence