CVE-2026-6762Network attack vector

Content spoofing via undisclosed DOM flaw

Published Apr 21, 2026 · Updated Apr 21, 2026

Spoofing in the DOM Core & HTML component in Mozilla Firefox and Thunderbird allows remote attackers to display deceptive web content. Mozilla has not disclosed the specific DOM locus or incorrect operation that permits the spoofing, and the referenced security bug is access-restricted. Exploitation requires user interaction; Thunderbird disables scripting while reading mail, limiting exposure there to browser or browser-like contexts.

CVSS severity6.3
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Spoofing in the DOM Core & HTML component in Mozilla Firefox and Thunderbird allows remote attackers to display deceptive web content. Mozilla has not disclosed the specific DOM locus or incorrect operation that permits the spoofing, and the referenced security bug is access-restricted. Exploitation requires user interaction; Thunderbird disables scripting while reading mail, limiting exposure there to browser or browser-like contexts.

The record

CVE
CVE-2026-6762
Published
Apr 21, 2026
Updated
Apr 21, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-290
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/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-290Authentication Bypass by Spoofing

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo