CVE-2021-25262Network attack vector

Website impersonation via IDN homograph spoofing

Published May 21, 2025 · Updated May 21, 2025

Improper output encoding in Yandex Browser for Android before 21.3.0 allows remote attackers to impersonate websites with IDN homographs. The vendor identifies improper output encoding but has not disclosed the component or the exact normalization, rendering, or display error. Exploitation requires active user interaction with an attacker-controlled internationalized domain and can expose information through a convincingly spoofed site.

CVSS severity6.9
Medium
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper output encoding in Yandex Browser for Android before 21.3.0 allows remote attackers to impersonate websites with IDN homographs. The vendor identifies improper output encoding but has not disclosed the component or the exact normalization, rendering, or display error. Exploitation requires active user interaction with an attacker-controlled internationalized domain and can expose information through a convincingly spoofed site.

The record

CVE
CVE-2021-25262
Published
May 21, 2025
Updated
May 21, 2025
Vendor
Yandex
Product
Yandex Browser
Classifications
CWE-116, CAPEC-113
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 2025CVE publishedPublication date reported by the CVE source.
  2. May 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=21.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Yandex · Yandex Browserversion=21.3.0

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
6.9YandexCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output
CAPEC-113Interface Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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