Cyber Resilience

CVE-2026-16410

Memory Safety in Mozilla Firefox ≤ 153.0.0

Published
21 July 2026
Modified
24 July 2026
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0031 23th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-16410 is a critical-severity Type Confusion (CWE-843) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 23th 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 SI-2 (Flaw Remediation) and CM-7 (Least Functionality) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

CWE(s)

Related Threats

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?

Type confusion (CWE-843) in browser JIT enables client-side RCE via malicious JavaScript, directly mapping to T1203.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-2796Same product: Mozilla Firefox
CVE-2026-16363Same product: Mozilla Firefox
CVE-2024-7652Same product: Mozilla Firefox
CVE-2026-16355Same product: Mozilla Firefox
CVE-2025-9187Same product: Mozilla Firefox
CVE-2026-7322Same product: Mozilla Firefox
CVE-2026-12312Same product: Mozilla Firefox
CVE-2026-8973Same product: Mozilla Firefox
CVE-2019-11707Same product: Mozilla Firefox
CVE-2025-9185Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 153.0.0
mozilla
thunderbird
≤ 153.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • CM-7 Least Functionality
  • SC-39 Process Isolation
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.5.2
  • V3.2.3
  • V15.3.5

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires applying the vendor-supplied patch that corrects the JIT miscompilation in Firefox/Thunderbird 153.

prevent

Allows disabling or restricting JIT compilation features to reduce the attack surface for type-confusion flaws in the JS engine.

prevent

Process isolation limits the blast radius of successful type-confusion exploitation within the browser's JavaScript engine.

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 type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional weaknesses.

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.

detects

Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.

prevents

Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.

prevents

Application security requirements can specify strong typing and interface contracts that reduce type confusion.

prevents

Secure architecture principles promote type-safe languages and memory-safety mechanisms that mitigate type confusion.

prevents

Secure coding standards directly forbid unsafe type casts and require static-analysis checks for type confusion.

References