Fenrir Sleipnir Mobile up to 3.8.x Fullscreen API clickjacking

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.2$0-$5k4.05

Summaryinfo

A vulnerability was found in Fenrir Sleipnir Mobile up to 3.8.x. It has been rated as problematic. This vulnerability affects unknown code of the component Fullscreen API. The manipulation leads to clickjacking. This vulnerability is listed as CVE-2026-109434. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Fenrir Sleipnir Mobile up to 3.8.x. It has been rated as problematic. This issue affects an unknown function of the component Fullscreen API. The manipulation with an unknown input leads to a clickjacking vulnerability. Using CWE to declare the problem leads to CWE-451. The user interface (UI) does not properly represent critical information to the user, allowing the information - or its source - to be obscured or spoofed. This is often a component in phishing attacks. Impacted is integrity. The summary by CVE is:

Fenrir Sleipnir Browser for Android before 3.9.0 contains a UI spoofing vulnerability that allows remote attackers to impersonate the browser's trusted address bar by entering fullscreen mode via the Fullscreen API without displaying a persistent notification or trusted-origin indicator. Attackers can render a counterfeit address bar showing a trusted origin over attacker-controlled content after a single user tap, enabling credential harvesting, malware delivery, or social engineering through fake login, update, or payment pages.

The advisory is shared at fenrir-inc.com. The identification of this vulnerability is CVE-2026-109434 since 10/12/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1566.003 for this issue.

Upgrading to version 3.9.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.3
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Clickjacking
CWE: CWE-451
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Sleipnir Mobile 3.9.0

Timelineinfo

10/12/2026 CVE reserved
10/19/2026 +7 days Advisory disclosed
10/19/2026 +0 days VulDB entry created
10/19/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: fenrir-inc.com
Status: Confirmed

CVE: CVE-2026-109434 (🔒)
GCVE (CVE): GCVE-0-2026-109434
GCVE (VulDB): GCVE-100-422513

Entryinfo

Created: 10/19/2026 20:51
Changes: 10/19/2026 20:51 (75)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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