CVE-2026-26240: qnap systems inc. file station 5 Stack-based Buffer Overflow
CVSS: 9.1v3.1CriticalModified
Published 10-06-2026Last modified 17-06-2026
Vulnerability summary
CVE-2026-26240 is a critical (CVSS 9.1) Stack-based Buffer Overflow vulnerability in qnap systems inc. file station 5. EPSS estimates a 0.56% chance of exploitation in the next 30 days, higher than 45.8% of scored vulnerabilities.
CVSS score
9.1/10
010
Critical · v3.1 (NVD)EPSS score
0.56%
0%100%
Low · +0.12 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 10-06-2026PublishedVulnerability first disclosed.
- 17-06-2026Last modifiedVulnerability information updated.
Description
A buffer overflow vulnerability has been reported to affect File Station 5. The remote attackers can then exploit the vulnerability to modify memory or crash processes. We have already fixed the vulnerability in the following version: File Station 5 5.5.6.5243 and later
CVSS metrics
3 scores · 2 sources · 2 versionsLow 1.3Preferred score · CVE.org (CNA)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:USourcesAll 2 agree
- NVDNIST1.3LowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/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
Critical 9.1Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HSourcesSingle source
EPSS trend
Probability
0.56%
Chance of exploitation in the next 30 days
Percentile
46%
Versus all other CVEs
30-day change
+0.12 pp
From 0.44% on 21-09-2026
21-09-202621-10-2026
EPSS score0.56%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Qnap1 product
- file_station≥ 5.5.6.4691, < 5.5.6.5243
Qnap systems inc.1 product
- file station 5≥ 5.5.0, < 5.5.6.5243
2 vendors · 2 products