CVE-2025-13476

Name: CVE-2025-13476
Creator: NVD / NIST
Published: 2026-03-05T19:15:58.283+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.34%

Last modified Jun 17, 2026

CVE-2025-13476 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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). EPSS estimates a 0.34% chance of exploitation in the next 30 days.

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)

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.34%

26.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-327

Affected Software

Vendor	Product	Versions	Update
Rakuten	Viber	>= 25.6.0, <= 25.8.1.0	—
Rakuten	Viber	9.3.0.6	25.7.2.0g

References

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

Timeline

Published: Mar 5, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-13476?

How severe is CVE-2025-13476?

CVE-2025-13476 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.34% probability of exploitation in the next 30 days.

How do I fix CVE-2025-13476?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-13476?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST