Cyber Posture

CVE-2025-8035

High

Published: 22 July 2025

Published
22 July 2025
Modified
13 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0011 29.1th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-8035 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 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 29.1th 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

Flaw remediation requires timely patching of the specific memory safety bugs in vulnerable Firefox and Thunderbird versions, directly eliminating the vulnerability.

prevent

Memory protection implements controls like ASLR and non-executable memory to prevent arbitrary code execution from memory corruption exploits in this CVE.

detect

Vulnerability monitoring and scanning identifies systems running affected Firefox and Thunderbird versions, enabling targeted 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 in browser/email client directly enables client-side RCE via malicious site/content (T1203 Exploitation for Client Execution).

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

NVD Description

Memory safety bugs present in Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140 and Thunderbird 140. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of…

more

these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

Deeper analysisAI

CVE-2025-8035 is a set of memory safety bugs classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) affecting multiple versions of Mozilla products, specifically Firefox ESR 128.12, Thunderbird ESR 128.12, Firefox ESR 140.0, Thunderbird ESR 140.0, Firefox 140, and Thunderbird 140. These bugs involve memory corruption issues, with some demonstrating evidence of such corruption, leading to a presumption that sufficient effort could enable arbitrary code execution.

The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating it is exploitable over the network with low attack complexity, no required privileges, but necessitating user interaction. Remote attackers can target users of affected browsers or email clients, tricking them into performing an action such as visiting a malicious website or processing crafted content, potentially achieving arbitrary code execution with high impacts on confidentiality, integrity, and availability.

Mozilla security advisories (MFSA 2025-56, 58, 59, and 61) and the associated Bugzilla entry detail the fixes applied in updated releases: Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1. Security practitioners should prioritize upgrading to these patched versions to mitigate the risks, as no workarounds are specified in the provided references.

Details

CWE(s)

Affected Products

mozilla
firefox
≤ 128.13.0 · ≤ 141.0 · 140.0 — 140.1.0
mozilla
thunderbird
≤ 128.13.0 · ≤ 141.0 · 140.0 — 140.1.0

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References