Cyber Resilience

CVE-2026-16408

Memory Safety in Mozilla Firefox ≤ 153.0.0

Published
21 July 2026
Modified
22 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 0.0034 26th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-16408 is a critical-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 26th 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Integer overflow in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Integer overflow in client-side media playback enables memory corruption/RCE when processing attacker-controlled content (e.g., malicious webpage or file), directly mapping to drive-by compromise and client execution exploitation.

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

CVEs Like This One

CVE-2026-16395Same product: Mozilla Firefox
CVE-2026-5732Same product: Mozilla Firefox
CVE-2026-2781Same product: Mozilla Firefox
CVE-2026-2762Same product: Mozilla Firefox
CVE-2026-16394Same product: Mozilla Firefox
CVE-2026-10702Same product: Mozilla Firefox
CVE-2026-16412Same product: Mozilla Firefox
CVE-2026-3847Same product: Mozilla Firefox
CVE-2025-11152Same product: Mozilla Firefox
CVE-2026-4691Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 153.0.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-2 Flaw Remediation
  • SI-10 Information Input Validation
  • SI-16 Memory Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires timely application of the vendor patch that eliminates the integer overflow in the Audio/Video playback parser.

prevent

Enforces validation of untrusted media input streams before they reach the vulnerable integer-handling code.

prevent

Applies memory-protection techniques that block exploitation of the overflow once it occurs in the playback component.

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 require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

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 integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

References