Cyber Posture

CVE-2025-9184

High

Published: 19 August 2025

Published
19 August 2025
Modified
13 April 2026
KEV Added
Patch
CVSS Score 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0010 27.4th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-9184 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Mozilla Firefox. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 27.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Client Execution (T1203). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires timely identification, reporting, and correction of software flaws like the memory safety bugs in CVE-2025-9184 through vendor patches.

prevent

Implements runtime memory protections such as ASLR and DEP to directly mitigate exploitation of memory corruption vulnerabilities in CVE-2025-9184.

prevent

Ensures organizations receive and act on vendor security advisories like Mozilla's MFSA for CVE-2025-9184 to enable rapid flaw remediation.

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Memory corruption bugs enabling remote arbitrary code execution in client software (browser/email) directly map to exploitation for client execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to…

more

run arbitrary code. This vulnerability was fixed in Firefox 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird 140.2.

Deeper analysisAI

CVE-2025-9184 encompasses multiple memory safety bugs affecting Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141, and Thunderbird 141. These bugs include instances showing evidence of memory corruption, which Mozilla presumes could be exploited with sufficient effort to achieve arbitrary code execution. The vulnerability is classified under CWE-119 (improper restriction of operations within the bounds of a memory buffer) and NVD-CWE-noinfo, with a CVSS v3.1 base score of 8.1 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H).

Remote attackers require no privileges or user interaction to exploit this vulnerability over the network, though it demands high attack complexity. Successful exploitation could result in high-impact confidentiality, integrity, and availability violations, potentially enabling arbitrary code execution within the affected browser or email client processes.

Mozilla's security advisories (MFSA 2025-64, 67, 70, and 72) detail the fixes applied in Firefox 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird ESR 140.2. Security practitioners should prioritize updating to these patched versions and monitor the linked Bugzilla entries for additional technical details on the individual bugs (1929482, 1976376, 1979163, 1979955).

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 140.2.0 · ≤ 142.0
mozilla
thunderbird
≤ 140.2.0 · ≤ 142.0

CVEs Like This One

CVE-2026-4710Same product: Mozilla Firefox
CVE-2025-9185Same product: Mozilla Firefox
CVE-2025-9179Same product: Mozilla Firefox
CVE-2025-8035Same product: Mozilla Firefox
CVE-2026-0891Same product: Mozilla Firefox
CVE-2026-5731Same product: Mozilla Firefox
CVE-2026-6752Same product: Mozilla Firefox
CVE-2026-0892Same product: Mozilla Firefox
CVE-2026-6776Same product: Mozilla Firefox
CVE-2026-2779Same product: Mozilla Firefox

References