What is the CVSS score of CVE-2026-0839?

CVE-2026-0839 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of 520w Firmware are affected by CVE-2026-0839?

Organizations using A weakness face significant risk from CVE-2026-0839, a buffer overflow vulnerability rated CVSS 8.8.

Is there a public PoC exploit available for CVE-2026-0839?

Yes, a public proof-of-concept exploit is available for CVE-2026-0839. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2026-0839?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

520w Firmware CVE-2026-0839

HIGH

Buffer Overflow (CWE-119)

2026-01-11 cna@vuldb.com

Buffer Overflow 520w Firmware

8.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Jan 13, 2026 - 21:57 vuln.today

Public exploit code

CVE Published

Jan 11, 2026 - 06:15 nvd

HIGH 8.8

DescriptionCVE.org

A weakness has been identified in UTT 进取 520W 1.7.7-180627. Affected is the function strcpy of the file /goform/APSecurity. Executing a manipulation of the argument wepkey1 can lead to buffer overflow. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

AnalysisAI

Remote code execution in UTT 520W Firmware 1.7.7-180627 via buffer overflow in the /goform/APSecurity endpoint allows authenticated attackers to achieve full system compromise through manipulation of the wepkey1 parameter. Public exploit code exists for this vulnerability and the vendor has not released a patch despite early notification. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access

Authenticate to device

Exploit

Send crafted wepkey1 parameter

Execution

Overflow strcpy buffer in /goform/APSecurity

Impact

Execute arbitrary code

Access

Authenticate to device

Exploit

Send crafted wepkey1 parameter

Execution

Overflow strcpy buffer in /goform/APSecurity

Impact

Execute arbitrary code

Vulnerability AssessmentAI

Exploitation	Attacker must authenticate to UTT 进取 520W device (version 1.7.7-180627). … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	CVSS 8.8 (HIGH). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	A remote attacker could exploit this vulnerability to buffer overflow.
Remediation	Monitor vendor advisories for a patch. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 7 days: Identify all affected systems and apply vendor patches promptly. …

Threat intelligence, references, and detailed analysis are available after sign-in.

CVE-2026-0839 vulnerability details – vuln.today

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520w Firmware CVE-2026-0839

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

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Attack ChainAIDerived

Vulnerability AssessmentAI

Recommended ActionAI

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External POC / Exploit Code