CVE-2021-21135
MEDIUMEPSS 97th pctlDescription
Inappropriate implementation in Performance API in Google Chrome prior to 88.0.4324.96 allowed a remote attacker to leak cross-origin data via a crafted HTML page.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Exploit Intelligence
Very high risk: more likely to be exploited than 97% of all known CVEs.
References
Related Vulnerabilities
Other CWE-346 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-34291 | High | 8.8 | 84% | KEV | - |
| CVE-2009-1185 | High | 7.2 | 82% | - | Fix |
| CVE-2020-16952 | High | 8.6 | 71% | - | - |
| CVE-2023-29711 | Critical | 9.8 | 70% | - | - |
| CVE-2015-4495 | High | 8.8 | 69% | KEV | Fix |
| CVE-2024-23898 | High | 8.8 | 67% | - | Fix |
Common questions
How do I fix CVE-2021-21135?
Published advisories record a fix for 9 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2021-21135 being actively exploited?
Not that we know of. CVE-2021-21135 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 19.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 97% of all scored CVEs.
How severe is CVE-2021-21135?
CVE-2021-21135 has a CVSS v3 base score of 6.5, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-21135 affect?
Published advisories record a fix for chromium (Debian), Google Chrome (Windows application), Google Chrome (EXE) (Windows application), Google Chrome Beta (Windows application), and 5 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.