What is the CVSS score of CVE-2025-3839?

CVE-2025-3839 has a contested CVSS base score of 8.0 from a third party (e.g. CISA-ADP), while the vendor rates it High. vuln.today uses the vendor rating as authoritative.

How to fix or mitigate CVE-2025-3839?

Within 24 hours: Inventory all systems running Epiphany and assess exposure in your environment; disable Epiphany's external URL handler functionality if operationally feasible. Within 7 days: Implement network-level restrictions on URL handler protocols and conduct user awareness training on suspicious link interactions. Within 30 days: Monitor vendor communications for patch availability; evaluate alternative browsers or endpoint isolation strategies; conduct security assessments of connected third-party applications that may be exploited via this vector.

Suse CVE-2025-3839

HIGH

Product UI does not Warn User of Unsafe Actions (CWE-356)

2026-01-23 patrick@puiterwijk.org

RCE Suse

High

Disputed · 8.0 NVD

View

Vulnerability Assessment

Weakness	CWE CWE-356 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V3 - Web Frontend Security Product UI inconsistency
Impact	CVSS 8.0 (HIGH). Attack vector: Network. Complexity: High. Privileges required: None. User interaction: Required. Exploitable via remote/network.
Exploit ScenarioDerived	A remote attacker could exploit this flaw, potential code execution on the client device via trusted UI.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

Affected ProductsAI

Component: those.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

A flaw was found in Epiphany, a tool that allows websites to open external URL handler applications with minimal user interaction. This design can be misused to exploit vulnerabilities within those handlers, making them appear remotely exploitable. The browser fails to properly warn or gate this action, resulting in potential code execution on the client device via trusted UI behavior.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Sources disagree (Low–High)

NVD PRIMARY 8.0 HIGH

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

SUSE 3.1 LOW

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

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Patch released

Apr 06, 2026 - 02:30 nvd

Patch available

CVE Published

Jan 23, 2026 - 05:16 nvd

HIGH 8.0

DescriptionCVE.org

Executive ViewAI

Why It Matters

CVE-2025-3839 affects Epiphany's URL handler mechanism, which could allow attackers to remotely exploit vulnerabilities in third-party applications through malicious web content. Organizations using Epiphany-based systems face potential compromise of endpoints and connected applications without user awareness, creating a significant attack vector for credential theft and lateral movement.

Business Impact: High

Compensating Controls

Disable external URL handler functionality in Epiphany configuration; implement application whitelisting to restrict which handlers can be invoked; deploy network segmentation to isolate systems running Epiphany from sensitive resources; enforce strict outbound URL filtering via proxy/firewall; consider disabling or removing Epiphany in favor of patched alternatives; monitor for exploitation attempts via endpoint detection and response (EDR) tools.

Threat Intelligence Overview

EPSS Score

0.0%

Top 97% exploitable

Data Quality

3 sources

Confidence: Low

NVD

CVE.org

EPSS Vendor

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.