CVE-2024-21388Network attack vector

Unauthenticated elevation of privilege

Published Jan 30, 2024 · Updated May 29, 2025

Improper input validation in Microsoft Edge before 121.0.2277.98 allows remote attackers to elevate privileges via network content. Microsoft has not disclosed the affected component or the invalid input operation that crosses a privilege boundary. No credentials or user interaction are required, but exploitation depends on undisclosed high-complexity conditions and can alter data or interrupt the browser.

CVSS severity6.5
Medium
EPSS probability31.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Microsoft Edge before 121.0.2277.98 allows remote attackers to elevate privileges via network content. Microsoft has not disclosed the affected component or the invalid input operation that crosses a privilege boundary. No credentials or user interaction are required, but exploitation depends on undisclosed high-complexity conditions and can alter data or interrupt the browser.

The record

CVE
CVE-2024-21388
Published
Jan 30, 2024
Updated
May 29, 2025
Vendor
Microsoft
Product
Microsoft Edge (Chromium-based)
Classifications
CWE-20
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 30, 2024CVE publishedPublication date reported by the CVE source.
  2. May 29, 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=1.0.0 <121.0.2277.98

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Edge (Chromium-based)version=1.0.0 <121.0.2277.98

Published CVSS scores

6.5Microsoft CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L

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-20Improper Input Validation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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