CVE-2026-0879Network attack vector

Sandbox escape via incorrect graphics boundary conditions

Published Jan 13, 2026 · Updated Jan 13, 2026

Graphics boundary errors in Mozilla Firefox before 147 and Firefox ESR before 115.32 or 140.7 allow remote attackers to escape its sandbox. The public advisory identifies the Graphics component, but the linked bug requires permission and Mozilla has not disclosed the affected routine or the boundary operation performed incorrectly. The network-reachable flaw requires no authentication or user interaction and breaches the browser sandbox, enabling impact outside the compromised content process.

CVSS severity9.8
Critical
EPSS probability0.61%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Graphics boundary errors in Mozilla Firefox before 147 and Firefox ESR before 115.32 or 140.7 allow remote attackers to escape its sandbox. The public advisory identifies the Graphics component, but the linked bug requires permission and Mozilla has not disclosed the affected routine or the boundary operation performed incorrectly. The network-reachable flaw requires no authentication or user interaction and breaches the browser sandbox, enabling impact outside the compromised content process.

The record

CVE
CVE-2026-0879
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
Mozilla
Product
Firefox
Classifications
CWE-119, T1068
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 13, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <147

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <147
Mozilla · Firefox ESRversion=unspecified <115.32; version=unspecified <140.7

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-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1068Exploitation for Privilege Escalation

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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