CVE-2026-16370Network attack vector

Mitigation bypass via undisclosed DOM networking logic

Published Jul 21, 2026 · Updated Jul 21, 2026

Mitigation bypass in Mozilla Firefox and Thunderbird before 153 allows remote attackers to circumvent a protection in DOM networking. Mozilla has not disclosed the affected protection, the incorrect DOM networking operation, or the network input that triggers the bypass. Remote reachability requires neither authentication nor user interaction, while the resulting access remains undisclosed.

CVSS severity9.1
Critical
EPSS probability0.31%
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

Mitigation bypass in Mozilla Firefox and Thunderbird before 153 allows remote attackers to circumvent a protection in DOM networking. Mozilla has not disclosed the affected protection, the incorrect DOM networking operation, or the network input that triggers the bypass. Remote reachability requires neither authentication nor user interaction, while the resulting access remains undisclosed.

The record

CVE
CVE-2026-16370
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-693
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

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

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

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-693Protection Mechanism Failure

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