CVE-2025-10537

Arbitrary code execution via memory corruption

Published Sep 16, 2025 · Updated Sep 16, 2025

Memory-safety flaws in Mozilla Firefox and Thunderbird before 143 allow attackers to execute arbitrary code via unspecified vectors. Mozilla groups six security bugs under this CVE but has not disclosed the affected functions, faulty memory operations, or attacker-controlled inputs. Firefox ESR before 140.3 and Thunderbird ESR before 140.3 are affected; Thunderbird normally blocks exploitation through email because message scripting is disabled.

CVSS severityUnavailable
Unscored
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-safety flaws in Mozilla Firefox and Thunderbird before 143 allow attackers to execute arbitrary code via unspecified vectors. Mozilla groups six security bugs under this CVE but has not disclosed the affected functions, faulty memory operations, or attacker-controlled inputs. Firefox ESR before 140.3 and Thunderbird ESR before 140.3 are affected; Thunderbird normally blocks exploitation through email because message scripting is disabled.

The record

CVE
CVE-2025-10537
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-119, T1203
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2025Record 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 <143

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Mozilla · Firefoxversion=unspecified <143
Mozilla · Thunderbirdversion=unspecified <140.3; version=unspecified <143
Mozilla · Firefox ESRversion=unspecified <140.3

Published CVSS scores

No CVSS assessment is available in this record.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1203Exploitation for Client Execution

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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