Cyber Resilience

CVE-2026-16361

Memory Safety in Mozilla Firefox ≤ 115.38.0

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-2026-16361 is a critical-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) 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 SC-39 (Process Isolation) and SI-16 (Memory Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

Memory safety bugs present in Thunderbird ESR 140.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in…

more

Firefox ESR 115.38, Firefox ESR 140.13, and Thunderbird 140.13.

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?

Memory corruption (CWE-119) enabling arbitrary code execution in a client application directly maps to exploitation for client execution.

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

CVEs Like This One

CVE-2025-9187Same product: Mozilla Firefox
CVE-2026-12312Same product: Mozilla Firefox
CVE-2025-9185Same product: Mozilla Firefox
CVE-2026-7324Same product: Mozilla Firefox
CVE-2026-16350Same product: Mozilla Firefox
CVE-2026-12305Same product: Mozilla Firefox
CVE-2026-0886Same product: Mozilla Firefox
CVE-2026-12307Same product: Mozilla Firefox
CVE-2026-8954Same product: Mozilla Firefox
CVE-2026-0892Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 115.38.0 · 128.1.0 — 140.13.0
mozilla
thunderbird
≤ 140.13.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
Detect
Catch it (NIST detect / respond)
  • SI-7 Software, Firmware, and Information Integrity
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V17.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly implements memory protections (e.g., ASLR, DEP, guard pages) that block exploitation of the memory corruption bugs described in CVE-2026-16361.

prevent

Enforces process isolation / sandboxing so that memory-safety violations cannot easily escalate to arbitrary code execution with full system privileges.

detect

Requires integrity verification of software/firmware at runtime or load time, enabling detection of unauthorized code introduced via memory corruption.

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 (bounds checking, safe APIs, reviews) directly prevent this class of flaw.

ID.RA-01 partial match
prevents

Vulnerability scanning and code analysis directly surface buffer-boundary flaws.

ID.RA-08 partial match
prevents

Receiving and triaging vulnerability disclosures commonly includes buffer-related reports.

PR.AT-02 partial match
prevents

Developer training on secure coding reduces introduction of memory-buffer errors.

PR.PS-02 partial match
prevents

Patching replaces vulnerable code containing buffer-boundary defects.

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 catches out-of-bounds accesses before release, covering most instances of the weakness.

prevents

Secure development lifecycle mandates memory-safety practices that directly prevent buffer-boundary violations.

prevents

Application security requirements can specify memory-safety rules, but do not prescribe implementation details.

prevents

Secure architecture and engineering principles include memory-safe design patterns that mitigate buffer overflows.

prevents

Secure coding standards explicitly forbid unsafe buffer operations, directly eliminating CWE-119.

References