CVE-2026-12323Network attack vector

Interface-content spoofing

Published Jun 16, 2026 · Updated Jun 16, 2026

Spoofing in Mozilla Firefox and Thunderbird before 152 allows attackers to misrepresent interface content via unspecified vectors. Mozilla identifies the affected locus only as DOM: Core & HTML and has not disclosed the faulty operation or triggering element. A victim must render attacker-controlled content in a browser or browser-like context; ordinary Thunderbird mail reading disables scripting and is not an established route.

CVSS severity5.4
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Spoofing in Mozilla Firefox and Thunderbird before 152 allows attackers to misrepresent interface content via unspecified vectors. Mozilla identifies the affected locus only as DOM: Core & HTML and has not disclosed the faulty operation or triggering element. A victim must render attacker-controlled content in a browser or browser-like context; ordinary Thunderbird mail reading disables scripting and is not an established route.

The record

CVE
CVE-2026-12323
Published
Jun 16, 2026
Updated
Jun 16, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-1021
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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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

5.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/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-1021Improper Restriction of Rendered UI Layers or Frames

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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