How severe is CVE-2021-25255?

CVE-2021-25255 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-25255 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-25255?

CVE-2021-25255 affects Yandex Yandex Browser. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-25255?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-25255 have an EU (EUVD) identifier?

Yes. CVE-2021-25255 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-12166.

When was CVE-2021-25255 published?

CVE-2021-25255 was published on 2025-05-21 and last updated on 2026-06-17.

CVE-2021-25255

CVE-2021-25255 is a high-severity vulnerability in Yandex Yandex Browser with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.3
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-12166
Weakness: CWE-20
Affected product: Yandex Yandex Browser
Published: 2025-05-21
Last modified: 2026-06-17

Description

Yandex Browser Lite for Android prior to version 21.1.0 allows remote attackers to cause a denial of service.

Frequently asked questions

What is CVE-2021-25255?: Yandex Browser Lite for Android prior to version 21.1.0 allows remote attackers to cause a denial of service.
How severe is CVE-2021-25255?: CVE-2021-25255 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-25255 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-25255?: CVE-2021-25255 affects Yandex Yandex Browser. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-25255?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-25255 have an EU (EUVD) identifier?: Yes. CVE-2021-25255 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-12166.
When was CVE-2021-25255 published?: CVE-2021-25255 was published on 2025-05-21 and last updated on 2026-06-17.

References

https://yandex.com/bugbounty/i/hall-of-fame-browser/

Affected products (1)

cpe:2.3:a:yandex:yandex_browser:*:*:*:*:lite:android:*:*

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