Cyber Resilience

CVE-2025-1937

Mozilla Firefox ≤ 115.21.0

Public PoC
Published
04 March 2025
Modified
13 April 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0054 43th percentile
Risk Priority 56 floored blend · peak EPSS

Summary

CVE-2025-1937 is a high-severity Improper Handling of Overlap Between Protected Memory Ranges (CWE-1260) vulnerability in Mozilla Firefox. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Process Injection (T1055); ranked at the 43th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

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.

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-2025-1937 involves multiple memory safety bugs classified under CWE-1260, present in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, and Thunderbird 128.7. Some of these bugs demonstrated evidence of memory corruption, which Mozilla presumes could be exploited to achieve arbitrary code execution with sufficient effort. The vulnerability carries a CVSS v3.1 base score of 7.5.

Remote attackers can exploit CVE-2025-1937 over the network without privileges, though it requires high attack complexity and user interaction. Successful exploitation could result in high impacts to confidentiality, integrity, and availability, potentially enabling arbitrary code execution in the context of the affected browser or mail client.

Mozilla advisories MFSA2025-14, MFSA2025-15, MFSA2025-16, and MFSA2025-17 detail the fixes, which are available in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8. Additional technical details are provided in Bugzilla entries for bugs 1938471 and 1940716. Security practitioners should prioritize updating affected instances to mitigate this issue.

EU & UK References

Vulnerability Data

Memory safety bugs present in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, and Thunderbird 128.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been…

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exploited to run arbitrary code. This vulnerability was fixed in Firefox 136, Firefox ESR 115.21, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1055 Process Injection Stealth
Adversaries may inject code into processes in order to evade process-based defenses as well as possibly elevate privileges.
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
T1611 Escape to Host Privilege Escalation
Adversaries may break out of a container or virtualized environment to gain access to the underlying host.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-4778Same product: Mozilla Firefox
CVE-2025-4083Same product: Mozilla Firefox
CVE-2026-4692Same product: Mozilla Firefox
CVE-2026-12297Same product: Mozilla Firefox
CVE-2026-16393Same product: Mozilla Firefox
CVE-2026-16360Same product: Mozilla Firefox
CVE-2025-4092Same product: Mozilla Firefox
CVE-2025-5268Same product: Mozilla Firefox
CVE-2026-6764Same product: Mozilla Firefox
CVE-2026-16364Same product: Mozilla Firefox

Affected Assets

mozilla
firefox
≤ 115.21.0 · ≤ 128.8.0 · ≤ 135.0
mozilla
thunderbird
≤ 128.8.0 · 129.0 — 136.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Process isolation depends on correct non-overlapping memory protection domains.

Memory protection mechanisms must correctly handle ranges to block unauthorized execution or access.

Access enforcement directly stops bypass of memory protections that overlapping ranges would enable.

Isolating security functions requires non-overlapping protected memory ranges to avoid bypass.

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 development practices directly prevent flawed memory-range overlap logic in kernels and hypervisors.

ID.RA-01 partial match
prevents

Vulnerability identification can surface overlap defects after they are introduced but does not stop them at design time.

PR.AA-05 partial match
prevents

Enforcing access-control policy can include memory-range permissions, yet the weakness is an implementation flaw inside that enforcement.

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

Security testing in development and acceptance can detect overlap issues but does not itself prevent them.

prevents

Secure system architecture and engineering principles require explicit memory-range separation and protection mechanisms that directly prevent overlapping protected regions.

prevents

Secure coding standards mandate checks for address-range overlap and proper memory-protection configuration, mitigating the weakness at implementation time.

mitigates

Information access restriction policies rely on correct memory protection; eliminating overlap strengthens enforcement but does not define the policy.

References