CVE-2026-74964 in Firefox
Summary
by MITRE • 08/18/2026
Integer overflow in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1.
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Analysis
by VulDB Data Team • 08/18/2026
The identified security issue represents a critical integer overflow condition located within the graphics processing subsystem of Mozilla Firefox browsers. Integer overflows occur when an arithmetic operation results in a value that exceeds the maximum capacity of the allocated data type, causing it to wrap around to a negative number or a significantly smaller positive value than intended. In the context of browser rendering engines such as Gecko, this flaw typically manifests during memory allocation calculations for graphical buffers, texture mappings, or canvas operations. When an attacker can influence the inputs that drive these mathematical computations within the graphics component, they may cause the system to allocate insufficient memory based on a miscalculated size derived from the overflowed integer value. This discrepancy between the expected and actual allocated buffer sizes creates a dangerous state where subsequent write operations exceed the bounds of the allocated memory region.
The operational impact of this vulnerability is severe, as it can lead to heap-based buffer overflows that compromise the integrity of the browser process. By carefully crafting malicious web content or manipulating specific graphical API calls, an attacker could potentially execute arbitrary code with the privileges of the user running the application. This type of exploitation allows for full system compromise if the victim interacts with a specially constructed webpage or loads a compromised image file that triggers the flawed calculation logic within the graphics pipeline. The vulnerability affects multiple versions of Firefox including standard releases and Extended Support Release channels, indicating a systemic issue in the underlying rendering architecture rather than an isolated edge case.
From a classification perspective, this flaw aligns closely with CWE-190 Integer Overflow or Wraparound, which describes situations where arithmetic operations produce results that exceed the range representable by the integer type. Furthermore, exploitation techniques associated with such vulnerabilities often map to MITRE ATT&CK tactics involving Initial Access and Execution, specifically through browser-based attacks like CVE-driven exploits in web content rendering engines. The persistence of this issue across multiple major releases underscores the complexity involved in securing low-level memory management routines within high-performance graphics subsystems where performance optimizations sometimes bypass rigorous bounds checking mechanisms.
Mitigation strategies primarily rely on applying the vendor-provided patches that address these specific calculation errors by implementing proper range checks before performing arithmetic operations or using safe integer types that prevent wraparound behavior. Users must ensure their browsers are updated to Firefox version 154, Firefox ESR 140.14, or Firefox ESR 153.1 where the underlying logic has been corrected to validate input sizes and handle potential overflow conditions gracefully without compromising memory safety. Additionally, defense-in-depth measures such as enabling automatic security updates, utilizing browser sandboxing features that isolate rendering processes from critical system resources, and deploying network-level filtering to block access to untrusted or suspicious web content can significantly reduce the attack surface available for exploiting this class of vulnerabilities until all endpoints are fully patched.