CVE-2026-2785

Memory Safety in Mozilla Firefox ≤ 140.8.0

Memory Safety

Published

24 February 2026

Modified

13 April 2026

Patch / advisory

View advisory

CVSS Score v3.1 9.8

Click a component to see what it means

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0037 30th percentile

Risk Priority 71 floored blend · peak EPSS

Summary

CVE-2026-2785 is a critical-severity Access of Uninitialized Pointer (CWE-824) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 30th 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 SA-15 (Development Process, Standards, and Tools) — 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-2026-2785 is an invalid pointer vulnerability (CWE-824) in the JavaScript Engine component of Mozilla products. It affects Firefox versions prior to 148, Firefox ESR versions prior to 140.8, Thunderbird versions prior to 148, and Thunderbird versions prior to 140.8. The issue has a CVSS v3.1 base score of 9.8, indicating critical severity.

Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity. Successful exploitation can result in high impacts to confidentiality, integrity, and availability, potentially allowing arbitrary code execution within the context of the affected browser or email client.

Mozilla security advisories (MFSA 2026-13, 15, 16, and 17) and the associated Bugzilla entry detail the patch releases that address the vulnerability. Mitigation involves updating to Firefox 148, Firefox ESR 140.8, Thunderbird 148, or Thunderbird 140.8, as these versions include the necessary fixes for the invalid pointer dereference in the JavaScript Engine.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-8506

Vulnerability Data

Invalid pointer in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CWE(s): CWE-824

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.

attack.mitre.org →

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.

attack.mitre.org →

T1203 Exploitation for Client Execution Execution

Adversaries may exploit software vulnerabilities in client applications to execute code.

attack.mitre.org →

T1210 Exploitation of Remote Services Lateral Movement

Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.

attack.mitre.org →

T1211 Exploitation for Stealth Stealth

Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.

attack.mitre.org →

T1212 Exploitation for Credential Access Credential Access

Adversaries may exploit software vulnerabilities in an attempt to collect credentials.

attack.mitre.org →

Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-16409Same product: Mozilla Firefox

CVE-2026-6757Same product: Mozilla Firefox

CVE-2026-2805Same product: Mozilla Firefox

CVE-2026-6748Same product: Mozilla Firefox

CVE-2026-6751Same product: Mozilla Firefox

CVE-2026-6749Same product: Mozilla Firefox

CVE-2026-6778Same product: Mozilla Firefox

CVE-2026-16353Same product: Mozilla Firefox

CVE-2025-1016Same product: Mozilla Firefox

CVE-2024-6615Same product: Mozilla Firefox

Affected Assets

mozilla

firefox

≤ 140.8.0 · ≤ 148.0

mozilla

thunderbird

≤ 140.8.0 · ≤ 148.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover uninitialized pointer accesses through static analysis, dynamic testing, or fuzzing before deployment.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented development processes and tools enables use of analyzers or coding standards that identify uninitialized pointer defects.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles can mandate memory-safety practices and language choices that structurally avoid uninitialized pointer use.

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 mostly match

prevents

Secure SDLC practices directly prevent uninitialized pointer bugs via coding standards, analysis, and reviews, but eliminating this single weakness only partially fulfills the broader control.

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.

A.8.29 Security testing in development and acceptance mostly match

finds

Security testing can detect uninitialized pointer usage before release.

A.8.25 Secure development life cycle partial match

prevents

Secure development life cycle mandates practices that reduce uninitialized pointer defects.

A.8.26 Application security requirements partial match

degrades

Application security requirements can specify pointer initialization rules.

A.8.27 Secure system architecture and engineering principles partial match

degrades

Secure architecture principles discourage unsafe pointer handling.