CVE-2025-66287
Published: 04 December 2025
Summary
CVE-2025-66287 is a high-severity Classic Buffer Overflow (CWE-120) vulnerability in Webkitgtk (inferred from references). Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 22.1th 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-2025-66287 is a vulnerability in WebKitGTK that allows processing of malicious web content to trigger an unexpected process crash due to improper memory handling, mapped to CWE-120 (Buffer Copy without Checking Size of Input). Published on 2025-12-04, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high severity with significant potential impacts across confidentiality, integrity, and availability.
Remote attackers require no privileges and can exploit this over the network with low attack complexity, but it necessitates user interaction, such as visiting a malicious webpage or opening crafted content in an affected application. Exploitation leads to process crashes and, per the CVSS metrics, high-level compromise of confidentiality, integrity, and availability, potentially enabling broader system impacts depending on the context of WebKitGTK usage.
Red Hat has issued multiple security advisories with patches addressing this vulnerability, including RHSA-2025:22789, RHSA-2025:22790, RHSA-2025:23110, RHSA-2025:23433, and RHSA-2025:23434, recommending affected users apply the updates promptly to mitigate risks.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-201244
Vulnerability details
A flaw was found in WebKitGTK. Processing malicious web content can cause an unexpected process crash due to improper memory handling.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability in WebKitGTK allows remote exploitation via malicious web content requiring user interaction, directly enabling Exploitation for Client Execution (T1203) through buffer overflow leading to process compromise.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the WebKitGTK memory handling flaw (CWE-120) by requiring timely application of vendor patches such as those issued in RHSA-2025 advisories.
Implements memory protections like ASLR, DEP, and stack guards to prevent exploitation of buffer copy without size checking vulnerabilities in WebKitGTK.
Validates web content inputs to WebKitGTK to restrict malformed or oversized data that could trigger the improper memory handling leading to process crashes.