CVE-2025-3032Network attack vector

Sandbox escape via inherited fork-server descriptors

Published Apr 1, 2025 · Updated Apr 13, 2026

Privilege escalation in Mozilla Firefox and Thunderbird before 137 allows remote attackers to escape a Linux web content sandbox. The fork server passes unused crash-reporter and sandbox-reporter descriptors and retains its IPC descriptor when forking content processes. A compromised content process must race the fork server, steal an initial channel identifier, and impersonate the fork server or another child process.

CVSS severity7.4
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Mozilla Firefox and Thunderbird before 137 allows remote attackers to escape a Linux web content sandbox. The fork server passes unused crash-reporter and sandbox-reporter descriptors and retains its IPC descriptor when forking content processes. A compromised content process must race the fork server, steal an initial channel identifier, and impersonate the fork server or another child process.

The record

CVE
CVE-2025-3032
Published
Apr 1, 2025
Updated
Apr 13, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-403, T1068
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 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?

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

7.4CISA-ADPCVSS:3.1/AV:N/AC:H/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.

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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-403Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')
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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