CVE-2026-16353Network attack vector

Unspecified impact via invalid WebIDL pointer

Published Jul 21, 2026 · Updated Jul 21, 2026

Invalid pointer handling in DOM Bindings (WebIDL) in Mozilla Firefox and Thunderbird allows remote attackers to cause unspecified impact. Mozilla identifies the affected locus but has not disclosed which invalid pointer operation occurs or what input triggers it. CISA assesses network reachability without privileges or user interaction, while public sources do not establish whether exploitation causes memory corruption, code execution, or a crash.

CVSS severity9.8
Critical
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Invalid pointer handling in DOM Bindings (WebIDL) in Mozilla Firefox and Thunderbird allows remote attackers to cause unspecified impact. Mozilla identifies the affected locus but has not disclosed which invalid pointer operation occurs or what input triggers it. CISA assesses network reachability without privileges or user interaction, while public sources do not establish whether exploitation causes memory corruption, code execution, or a crash.

The record

CVE
CVE-2026-16353
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-416, CWE-824, CWE-476
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 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

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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-416Use After Free
CWE-824Access of Uninitialized Pointer
CWE-476NULL Pointer Dereference

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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