CVE-2026-7320
Published: 28 April 2026
Summary
CVE-2026-7320 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Mozilla Firefox. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 17.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-7320 is an information disclosure vulnerability stemming from incorrect boundary conditions in the Audio/Video component of Mozilla Firefox and Thunderbird. It is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N). The flaw affects Firefox versions prior to 150.0.1, Firefox ESR prior to 140.10.1 and 115.35.1, Thunderbird prior to 150.0.1, and Thunderbird prior to 140.10.1.
A remote attacker can exploit this vulnerability over the network with low complexity, requiring no privileges, user interaction, or special conditions. Successful exploitation allows the attacker to read sensitive data from the affected process, achieving high-impact confidentiality loss without affecting integrity or availability.
Mozilla's security advisories (MFSA 2026-35 through 2026-38) and the associated Bugzilla entry (bug 2027433) detail the patch deployment in the listed fixed releases. Security practitioners should prioritize updating affected Firefox and Thunderbird installations to mitigate the risk, as no additional workarounds are specified in the provided references.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26057
Vulnerability details
Information disclosure due to incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 150.0.1, Firefox ESR 140.10.1, Firefox ESR 115.35.1, Thunderbird 150.0.1, and Thunderbird 140.10.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Client-side information disclosure in browser/email client AV component enables remote exploitation via malicious web content or media streams, directly facilitating drive-by compromise for data collection from the process.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly mitigates the vulnerability by requiring timely identification, reporting, and correction of flaws like this buffer over-read through vendor patches such as Firefox 150.0.1.
Implements memory protection mechanisms like ASLR and guard pages that prevent exploitation of memory buffer boundary condition errors leading to information disclosure.
Requires validation of audio/video inputs with proper boundary checks to address the root cause of improper restriction of operations within memory buffer bounds.