Threat Intelligence / CVE / CVE-2025-62858

CVE-2025-62858 — QNAP Systems Inc. QTS

CVSS v3.1 6.5 (MEDIUM) · CVSS v4.0 5.1 · EPSS 0.3% (higher than 21.8% of all scored CVEs) · Priority 4.1/10 · Published 2026-06-09

As of 2026-06-09, CVE-2025-62858 is a MEDIUM-severity vulnerability in QNAP Systems Inc. QTS, CVSS v3.1 6.5, EPSS 0.3% (21.8th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2025-62858, most recently “QNAP QSA-26-10: Multiple Injection and Memory-Safety Vulnerabilities in QTS, QuTS hero, QuTS cloud, QVP, and File Station (CVE-2025-66273, CVE-2026-26240, and 12 others)”.

Last updated: 2026-06-09

What is CVE-2025-62858?

A buffer overflow vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to modify memory or crash processes. We have already fixed the vulnerability in the following versions: QTS 5.2.9.3410 build 20260214 and later QuTS hero h5.2.9.3410 build 20260214 and later QuTS hero h5.3.4.3500 build 20260520 and later QuTS hero h6.0.0.3397 build 20260206 and later

The record classifies CVE-2025-62858 under weakness class CWE-121. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs high-privilege credentials, needs no user interaction, and has high impact on integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 95 days ago.

Severity and exploitation probability

CVSS v3.1 base score
6.5 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H
CVSS v4.0 base score
5.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
EPSS (FIRST)
0.3% probability of exploitation in the next 30 days, higher than 21.8% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
4.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-06-09

Is CVE-2025-62858 being exploited?

No public exploitation evidence for CVE-2025-62858 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-06-09. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.

Affected products and versions

How to fix CVE-2025-62858

No vendor patch reference has been recorded for CVE-2025-62858 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2025-62858

1 tracked threat in the Threadlinqs corpus references CVE-2025-62858, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.

Other references

Full detection coverage & IOCs for threats exploiting CVE-2025-62858 are available via the Threadlinqs MCP server (Purple tier). View plans →

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