CVE-2026-84131Network attack vector

Privilege escalation via invalid Graphics pointer

Published Sep 1, 2026 · Updated Sep 2, 2026

Invalid-pointer handling in the Graphics component of Mozilla Firefox and Thunderbird allows remote attackers to escalate privileges. Mozilla has not disclosed the pointer's code-level locus or the operation that releases, retains, or dereferences it; the linked bug is access-restricted. CISA's assessment requires user interaction but no prior privileges, and Mozilla states that Thunderbird mail reading disables scripting, limiting ordinary email exposure.

CVSS severity8.8
High
EPSS probability0.33%
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

Invalid-pointer handling in the Graphics component of Mozilla Firefox and Thunderbird allows remote attackers to escalate privileges. Mozilla has not disclosed the pointer's code-level locus or the operation that releases, retains, or dereferences it; the linked bug is access-restricted. CISA's assessment requires user interaction but no prior privileges, and Mozilla states that Thunderbird mail reading disables scripting, limiting ordinary email exposure.

The record

CVE
CVE-2026-84131
Published
Sep 1, 2026
Updated
Sep 2, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-763
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

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

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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-763Release of Invalid Pointer or Reference

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