Cyber Resilience

CVE-2026-3845

Memory Safety in Mozilla Firefox ≤ 148.0.2

Published
10 March 2026
Modified
13 April 2026
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0044 37th percentile
Risk Priority 64 floored blend · peak EPSS

Summary

CVE-2026-3845 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Mozilla Firefox. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-3845 is a heap buffer overflow vulnerability (CWE-122) in the Audio/Video: Playback component of Firefox for Android. The flaw allows memory corruption when processing certain media content during playback. It was publicly disclosed on March 10, 2026, and 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 high severity due to its potential for significant impact.

Remote attackers can exploit this vulnerability by tricking users into playing maliciously crafted media files or streams accessible over the network. No privileges are required, but user interaction is necessary, such as opening a specially crafted video or audio file in the browser. Successful exploitation could result in high confidentiality, integrity, and availability impacts, potentially enabling arbitrary code execution, data theft, or system compromise on the affected Android device.

Mozilla's security advisory (MFSA 2026-19) and the associated Bugzilla entry (bug 2020174) confirm that the vulnerability was addressed in Firefox for Android version 148.0.2. Security practitioners should prioritize updating affected devices to this version or later to mitigate the risk, and advise users to avoid playing untrusted media content from unverified sources.

EU & UK References

Vulnerability Data

Heap buffer overflow in the Audio/Video: Playback component in Firefox for Android. This vulnerability was fixed in Firefox 148.0.2.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-5694Same product: Mozilla Firefox
CVE-2024-7530Same product: Mozilla Firefox
CVE-2026-4684Same product: Mozilla Firefox
CVE-2026-4691Same product: Mozilla Firefox
CVE-2026-4696Same product: Mozilla Firefox
CVE-2023-5175Same product: Mozilla Firefox
CVE-2025-13020Same product: Mozilla Firefox
CVE-2024-4764Same product: Mozilla Firefox
CVE-2023-37209Same product: Mozilla Firefox
CVE-2024-4771Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 148.0.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.

Input validation enforces bounds checking on data written to heap buffers, directly stopping the overflow condition from being introduced.

Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.

Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development and acceptance can detect heap overflows before release.

prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

prevents

Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.

none

Change management ensures controlled deployment of fixes for discovered heap-overflow vulnerabilities.

References