CVE-2026-92030: 
Rocky Linux vulnerability analysis and mitigation

CVE-2026-92030 is a mitigation bypass vulnerability in the DOM: Copy & Paste and Drag & Drop component of Mozilla Firefox and Thunderbird. Discovered and reported by researcher "anas cherni" (referenced via Bugzilla bug 2058417), it was publicly disclosed on September 15, 2026. Affected products include Firefox prior to version 156, Firefox ESR prior to 140.16 and 153.3, Thunderbird prior to 156, and Thunderbird ESR prior to 140.16 and 153.3. It carries a CVSS v3.1 base score of 5.4 (Medium) (Mozilla Advisory mfsa2026-92, Mozilla Advisory mfsa2026-90).

The vulnerability is classified under CWE-693 (Protection Mechanism Failure), indicating that an existing browser security mitigation in the DOM's Copy & Paste and Drag & Drop subsystem can be bypassed (Mozilla Advisory mfsa2026-92). The attack vector is network-based and requires user interaction — an attacker would need to lure a victim into performing a copy/paste or drag-and-drop action on a malicious web page. The precise technical mechanism (e.g., which specific mitigation is bypassed and how clipboard or drag data is manipulated) is not publicly detailed, as the underlying Bugzilla report (Bug 2058417) is access-restricted (Bugzilla). No public proof-of-concept code has been identified at this time.

Successful exploitation results in limited confidentiality and integrity impacts — specifically, low-level unauthorized read access to data and low-level unauthorized modification of data, with no availability impact (Mozilla Advisory mfsa2026-90). The bypass of clipboard/drag-and-drop protections could allow a malicious web page to read or inject content via user-initiated clipboard or drag operations, potentially exposing sensitive data copied by the user or enabling content injection into other contexts. The scope is unchanged, meaning exploitation is confined to the browser's security context without crossing privilege boundaries.

As of the disclosure date, there is no evidence of in-the-wild exploitation, no public proof-of-concept code, and no threat actor attribution associated with CVE-2026-92030. The EPSS score is approximately 0.164%, indicating a low probability of exploitation in the near term (Feedly). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires user interaction (a copy/paste or drag-and-drop action), which reduces the likelihood of automated or mass exploitation.

Mozilla has released patches addressing CVE-2026-92030 in Firefox 156, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird ESR 140.16, and Thunderbird ESR 153.3 (Mozilla Advisory mfsa2026-90, Mozilla Advisory mfsa2026-92, Mozilla Advisory mfsa2026-93). Users and administrators should update to the patched versions immediately. No configuration-based workarounds have been published; upgrading is the only recommended remediation. Enterprise users on ESR tracks should prioritize updating to ESR 140.16 or ESR 153.3 as appropriate for their deployment.

Mozilla rated this vulnerability as "moderate" impact in its September 15, 2026 security advisories, consistent with the CVSS 5.4 Medium score. Downstream Linux distributions including SUSE and openSUSE have issued security update announcements, and Red Hat has published errata (RHSA-2026:69461 and RHSA-2026:69462) addressing this and related Firefox vulnerabilities. No notable independent researcher commentary or significant social media discussion specific to this CVE has been identified beyond standard vulnerability tracking coverage.