CVE-2026-8960Network attack vector

Unauthenticated WebExtensions spoofing

Published May 19, 2026 · Updated May 19, 2026

Spoofing in WebExtensions in Mozilla Firefox and Thunderbird before 151 allows remote attackers to perform unspecified interface spoofing. Mozilla has not published the affected WebExtensions locus or the incorrect operation that permits the spoofing. No authentication or user interaction is required; available evidence identifies integrity impact but does not disclose what trusted content or state can be falsified.

CVSS severity7.5
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Spoofing in WebExtensions in Mozilla Firefox and Thunderbird before 151 allows remote attackers to perform unspecified interface spoofing. Mozilla has not published the affected WebExtensions locus or the incorrect operation that permits the spoofing. No authentication or user interaction is required; available evidence identifies integrity impact but does not disclose what trusted content or state can be falsified.

The record

CVE
CVE-2026-8960
Published
May 19, 2026
Updated
May 19, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-290
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 19, 2026CVE publishedPublication date reported by the CVE source.
  2. May 19, 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

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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-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

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Your stack

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