Cyber Resilience

CVE-2026-92038

Mozilla Firefox ≤ 153.3.0

Published
15 September 2026
Modified
05 October 2026
Patch / advisory
CVSS Score v3.1 9.1
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:N
EPSS Score 0.0035 27th percentile
Risk Priority 67 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-92038 is a critical-severity Protection Mechanism Failure (CWE-693) vulnerability in Mozilla Firefox. Its CVSS base score is 9.1 (Critical).

Operationally, ranked at the 27th 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 AC-3 (Access Enforcement) and AC-4 (Information Flow Enforcement) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Mitigation bypass in the Remote Settings Client component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

CWE(s)

Related Threats

CVEs Like This One

CVE-2026-16377Shared CWE-693
CVE-2026-16383Shared CWE-693
CVE-2026-17899Shared CWE-693
CVE-2026-79298Shared CWE-693
CVE-2026-11248Shared CWE-693
CVE-2026-56881Shared CWE-693
CVE-2024-11734Shared CWE-693
CVE-2026-34348Shared CWE-693
CVE-2023-25945Shared CWE-693
CVE-2023-39368Shared CWE-693

Affected Assets

mozilla
firefox
≤ 153.3.0 · 154.0.0 — 156.0.0
mozilla
thunderbird
≤ 153.3.0 · 154.0 — 156.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.3.3
  • V6.6.3
  • V10.2.2

Mitigating Controls (NIST 800-53 r5) AI

AC-3 directly requires enforcement of access authorizations via the protection mechanism itself.

AC-4 mandates use of information flow enforcement mechanisms to control data movement.

SC-2 requires separation of user and system functionality as a protection mechanism.

SC-28 requires protection mechanisms for information at rest.

SC-3 requires isolation of security functions from non-security functions.

SC-7 requires boundary protection mechanisms to monitor and control external communications.

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.AA-03 partial match
prevents

Enforcing authentication directly implements a core protection mechanism whose absence or misuse is the CWE.

PR.AA-05 partial match
prevents

Defining and enforcing access authorizations is a protection mechanism; proper use prevents the CWE.

PR.DS-01 partial match
prevents

Cryptographic and integrity controls are protection mechanisms whose correct deployment mitigates the CWE.

PR.DS-02 partial match
prevents

Encryption and integrity protections for transit are explicit protection mechanisms.

PR.IR-01 partial match
prevents

Logical network protections are protection mechanisms whose failure matches the CWE.

PR.PS-01 partial match
prevents

Hardened configuration baselines ensure protection mechanisms are correctly applied and maintained.

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

Systematic verification that security mechanisms operate according to defined standards reduces the likelihood that protection mechanisms are bypassed or disabled.

removes

A.8.26 only requires that security requirements (including protection mechanisms) be identified and specified during development or acquisition; it does not itself mandate, implement, or enforce the mechanisms that would remove CWE-693 instances from the product.

removes

A.8.28 mandates secure coding practices, principles, standards, design, peer review, defect removal, prohibition of insecure techniques (e.g. hard-coded passwords), and evaluation of common errors before deployment, which directly removes many instances of missing or incorrectly used protection mechanisms from first-party code; the bounded remainder is third-party components and post-deployment issues handled by other clauses (8.8, 8.29).

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248524 OL 8 must implement NIST FIPS-validated cryptography for the following: To provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. prevents CWE-693
  • V-248525 All OL 8 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at-rest protection. prevents CWE-693
Windows 10 (2 rules)
  • V-220865 The Windows Remote Management (WinRM) service must not use Basic authentication. prevents CWE-693
  • V-220812 Credential Guard must be running on Windows 10 domain-joined systems. prevents CWE-693
Windows Server 2016 (1 rule)
  • V-225012 Windows Server 2016 must be running Credential Guard on domain-joined member servers. prevents CWE-693
Windows Server 2019 (1 rule)
  • V-205907 Windows Server 2019 must be running Credential Guard on domain-joined member servers. prevents CWE-693

References