CVE-2026-16354 in Firefox
Summary
by MITRE • 07/21/2026
Information disclosure in the Graphics: ImageLib component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.
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Analysis
by VulDB Data Team • 07/21/2026
The vulnerability in question represents a critical information disclosure flaw within the Graphics ImageLib component of Mozilla Firefox browsers. This type of vulnerability falls under the broader category of information leakage mechanisms that can expose sensitive data to unauthorized parties. The issue specifically affects the image processing libraries used by Firefox for handling various graphic formats and operations, creating potential attack vectors through which adversaries might extract confidential information from system memory or process contexts. Such vulnerabilities are particularly concerning in browser environments where multiple applications and processes interact within a single execution space, making the attack surface more complex and potentially more dangerous.
The technical implementation of this flaw likely involves improper handling of memory management during image processing operations within the ImageLib component. When Firefox processes various graphic formats such as jpeg png or gif files, the underlying library may not properly sanitize memory access patterns or may fail to adequately validate input data before processing. This can lead to situations where adjacent memory regions containing sensitive information become accessible through crafted malicious content or by exploiting specific parsing behaviors in image handling code. The vulnerability could manifest through buffer overflows, use-after-free conditions, or improper memory deallocation that leaves residual data accessible to subsequent operations.
The operational impact of this information disclosure vulnerability extends beyond simple data exposure and can potentially enable more sophisticated attacks including privilege escalation or further exploitation chains. An attacker who successfully exploits this flaw might gain access to sensitive information such as cryptographic keys, session tokens, personal identification data, or other confidential system information that could be used for identity theft, financial fraud, or network infiltration. The severity of impact depends on the specific nature of information exposed and the execution context where the vulnerability occurs. According to industry standards such as CWE-200 (Information Exposure) and CWE-125 (Out-of-bounds Read), this vulnerability represents a significant risk to system confidentiality and data integrity.
The fix implemented in Firefox versions 153, Firefox ESR 115.38, and Firefox ESR 140.13 addresses the root cause through enhanced memory validation and proper input sanitization within the ImageLib component. These security updates likely include improved buffer management techniques, stricter validation of image data formats, and better handling of edge cases during image processing operations. Organizations should prioritize immediate deployment of these patches across all affected systems to mitigate the risk of exploitation. The mitigation strategy also includes monitoring network traffic for suspicious activity related to malformed image content and implementing proper security awareness training for users who might encounter potentially malicious web content.
From a threat modeling perspective, this vulnerability aligns with ATT&CK technique T1566 (Phishing) as attackers could craft malicious images to exploit the flaw, and T1005 (Data from Local System) as it enables information extraction from compromised systems. The remediation process should involve comprehensive testing of patched versions to ensure no regression in functionality while also monitoring for any potential side effects of the security updates. Security teams should maintain vigilance against similar vulnerabilities in other graphics processing libraries and maintain updated threat intelligence feeds to identify related exploitation attempts targeting this or similar classes of information disclosure vulnerabilities.