Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-2774 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 LSA Secrets (T1003.004); ranked in the top 48% of CVEs by exploit likelihood; 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-8 (Security and Privacy Engineering Principles) — 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-2026-2774 is an integer overflow vulnerability (CWE-190) in the Audio/Video component of Mozilla Firefox and Thunderbird products. It affects versions of Firefox prior to 148, Firefox ESR prior to 115.33 and 140.8, and Thunderbird prior to 148 and 140.8. The vulnerability was publicly disclosed on 2026-02-24 and carries a CVSS v3.1 base score of 9.8, indicating critical severity.
A remote attacker requires no privileges or user interaction to exploit this vulnerability over the network with low complexity. Successful exploitation can result in high-impact confidentiality, integrity, and availability violations, potentially allowing arbitrary code execution within the browser or application sandbox.
Mozilla's security advisories (MFSA 2026-13 through 2026-16) and the associated Bugzilla entry (bug 2014883) detail the fix applied in the listed versions. Security practitioners should prioritize updating affected Firefox and Thunderbird installations to the patched releases to mitigate the risk.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8496
Vulnerability Data
Integer overflow in the Audio/Video component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
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 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.