CVE-2021-37973

Name: CVE-2021-37973
Creator: NVD / NIST
Published: 2021-10-08T22:15:08.287+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.6/10Actively ExploitedEPSS 11.73%

Last modified Jun 17, 2026

CVE-2021-37973 is a critical-severity vulnerability rated 9.6/10 on the CVSS scale. Use after free in Portals in Google Chrome prior to 94.0.4606.61 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.. CISA has confirmed active exploitation in the wild. EPSS estimates a 11.73% chance of exploitation in the next 30 days.

Description

Use after free in Portals in Google Chrome prior to 94.0.4606.61 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.

Metrics

CVSS 3.1

9.6/10

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

EPSS Probability

11.73%

95.5th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Google	Chrome	< 94.0.4606.61
Fedoraproject	Fedora	33
Fedoraproject	Fedora	35
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop_24.htmlRelease Notes
https://crbug.com/1251727Issue Tracking, Patch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4DDW7HAHTS3SDVXBQUY4SURELO5D4X7R/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PM7MOYYHJSWLIFZ4TPJTD7MSA3HSSLV2/Release Notes
https://www.debian.org/security/2022/dsa-5046Mailing List, Third Party Advisory
https://chromereleases.googleblog.com/2021/09/stable-channel-update-for-desktop_24.htmlRelease Notes
https://crbug.com/1251727Issue Tracking, Patch, Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4DDW7HAHTS3SDVXBQUY4SURELO5D4X7R/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PM7MOYYHJSWLIFZ4TPJTD7MSA3HSSLV2/Release Notes
https://www.debian.org/security/2022/dsa-5046Mailing List, Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-37973US Government Resource

Timeline

Published: Oct 8, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-37973?

Use after free in Portals in Google Chrome prior to 94.0.4606.61 allowed a remote attacker who had compromised the renderer process to potentially perform a sandbox escape via a crafted HTML page.

How severe is CVE-2021-37973?

CVE-2021-37973 has a CVSS score of 9.6/10 (CRITICAL severity). The EPSS model estimates a 11.73% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-37973?

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-2021-37973?

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

Scan your code now

Source: NVD / NIST