CVE-2025-13476 — CRITICAL (9.8)

Q: How severe is CVE-2025-13476?

CVE-2025-13476 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Q: Is there a patch for CVE-2025-13476?

Check the references section above for vendor advisories and patch information. Affected products include: Rakuten Viber.

Vulnerability Description

Rakuten Viber Cloak mode in Android v25.7.2.0g and Windows v25.6.0.0–v25.8.1.0 uses a static and predictable TLS ClientHello fingerprint lacking extension diversity, allowing Deep Packet Inspection (DPI) systems to trivially identify and block proxy traffic, undermining censorship circumvention. (CWE-327)

CVSS Score

9.8

CRITICAL

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Rakuten	Viber	>= 25.6.0, <= 25.8.1.0

Related Weaknesses (CWE)

CWE-327

References

https://www.viber.com/en/download/Product
https://www.kb.cert.org/vuls/id/772695Third Party Advisory

FAQ

What is CVE-2025-13476?

CVE-2025-13476 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Rakuten Viber Cloak mode in Android v25.7.2.0g and Windows v25.6.0.0–v25.8.1.0 uses a static and predictable TLS ClientHello fingerprint lacking extension diversity, allowing Deep Packet Inspection (D...

How severe is CVE-2025-13476?

CVE-2025-13476 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2025-13476?

Check the references section above for vendor advisories and patch information. Affected products include: Rakuten Viber.