Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2025-1016 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 45th 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 SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — 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-2025-1016 encompasses multiple memory safety bugs, classified under CWE-787 (Out-of-bounds Write), present in Firefox 134, Thunderbird 134, Firefox ESR 115.19, Firefox ESR 128.6, Thunderbird 115.19, and Thunderbird 128.6. Some of these bugs demonstrated evidence of memory corruption, which Mozilla presumes could be exploited to run arbitrary code with sufficient effort. The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), marking it as critical.
Remote attackers can exploit these flaws over the network without requiring user privileges or interaction. Successful exploitation could enable arbitrary code execution within the context of the affected browser or email client, potentially leading to full compromise of the user's system through high-impact confidentiality, integrity, and availability violations.
Mozilla has mitigated CVE-2025-1016 with patches in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135. Security advisories MFSA 2025-07 through MFSA 2025-10, along with Bugzilla entries for bugs 1936601, 1936844, 1937694, 1938469, 1939583, and 1940994, provide further details on the fixes and affected components. Practitioners should prioritize updating affected products to these versions.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-1971
Vulnerability Data
Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 115.19, Firefox ESR 128.6, Thunderbird 115.19, and Thunderbird 128.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could…
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have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including fuzzing and bounds checks) finds out-of-bounds write flaws before deployment.
Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.
Input validation can structurally reject or sanitize data that would otherwise trigger an out-of-bounds write.
Memory-protection mechanisms limit the exploitability and blast radius of a successful out-of-bounds write.
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.
Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.
Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.
Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.
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.
Security testing in development and acceptance can detect and prevent out-of-bounds write defects.
Secure development life cycle mandates practices that prevent out-of-bounds writes.
Application security requirements can specify bounds-checking and safe memory handling.
Secure architecture and engineering principles reduce the likelihood of buffer overflows.
Secure coding directly addresses out-of-bounds writes through language choice and coding standards.
Change management can enforce review gates that catch unsafe memory operations before deployment.