Threat Intelligence Database

CVE-2026-84133 is a site isolation issue in the DOM: Push Subscriptions component of Mozilla Firefox. It was identified as a low impact vulnerability and fixed in Firefox 155. The vulnerability was internally found and reported by pakhunov.anton.n. The Mozilla Foundation released a security advisory on September 1, 2026, addressing this and multiple other vulnerabilities in Firefox 155. The CVSS 3.1 base score is 9.8, indicating a high severity from a technical perspective, but the vendor classified this specific issue as low impact. No known exploits in the wild have been reported. The vulnerability affects multiple Ubuntu LTS versions with specific mozjs52 package versions listed. No patch links were provided in the input, but the vendor advisory confirms the fix in Firefox 155.

CVE-2026-84134 is a security vulnerability affecting multiple specific versions of the mozjs52 JavaScript engine used in Ubuntu distributions. The vulnerability is classified with a high CVSS score of 9.8, indicating critical impact potential. However, the exact technical details of this vulnerability are not described in the source data. According to the Mozilla Foundation Security Advisory 2026-82, this issue is categorized as a low impact 'other issue' in the Profile Backup component and was fixed in Firefox 155. There are no known exploits in the wild. Multiple affected versions across Ubuntu 18.04, 20.04, 22.04, and 24.04 LTS releases are listed. The vendor advisory confirms that the vulnerability has been addressed in Firefox 155, providing an official fix.

CVE-2026-84135 is a security vulnerability affecting multiple specific versions of the mozjs52 JavaScript engine used in various Ubuntu LTS releases. The CVSS 3.1 score is 9.8, indicating critical severity with network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. The exact technical details of this vulnerability are not provided in the source data. Mozilla has fixed this and related vulnerabilities in Firefox 155, indicating an official patch is available. There are no known exploits in the wild at this time.

CVE-2026-84136 is a security vulnerability affecting multiple specific versions of the mozjs52 JavaScript engine component used in Firefox and related Ubuntu packages. The vulnerability is categorized as low impact and is described as an 'Other issue' in the DOM: Navigation component. It was fixed in Firefox 155 as part of a broader security update addressing multiple internally found bugs. The vulnerability has a high CVSS score of 9.8 but is assessed with low impact by the vendor advisory. There are no known exploits in the wild. Multiple Ubuntu LTS versions are affected by this vulnerability in the listed mozjs52 package versions.

CVE-2026-84137 is a spoofing vulnerability in the DOM: Core & HTML component of Mozilla Firefox. It was identified as a low impact issue and fixed in Firefox version 155. The vulnerability was internally found and is part of a set of security fixes addressing various memory corruption and security-relevant defects in Firefox 154 and ESR versions. The CVSS score is 9.8, indicating a high severity rating, but the vendor advisory classifies the impact of this specific issue as low. Multiple affected Ubuntu package versions of mozjs52 are listed, but the vulnerability is resolved in Firefox 155.

CVE-2026-84138 is a denial-of-service vulnerability in the PDF Viewer component of Firefox, fixed in Firefox 155. It was identified as part of a set of internally found bugs in Firefox 154 that showed evidence of memory corruption or other security-relevant defects. The vulnerability has a CVSS 3.1 score of 7.5 (medium severity) and does not involve confidentiality or integrity impacts but can cause availability disruption. Multiple Ubuntu LTS versions include affected mozjs52 package versions. No known exploits are reported in the wild. The vendor advisory confirms the issue is fixed in Firefox 155.

CVE-2026-84139 is a clickjacking vulnerability in the DOM: Events component of Firefox. It was fixed in Firefox 155 as part of a broader security update addressing multiple internally found bugs, some with memory corruption or security-relevant defects. The vulnerability has a high CVSS score of 9.8 but is rated medium severity in this context. No known exploits in the wild have been reported. The affected software versions include multiple specific builds of mozjs52 and Firefox versions distributed across Ubuntu 18.04, 20.04, 22.04, and 24.04 LTS releases.

CVE-2026-84140 is a security vulnerability related to a site isolation issue in the DOM: Navigation component of Mozilla Firefox. It was fixed in Firefox version 155 as part of a broader security update addressing multiple high-impact bugs. The vulnerability has a high CVSS score of 9.8, indicating critical impact potential, including confidentiality, integrity, and availability impacts. The affected product is mozjs52 as packaged in various Ubuntu LTS versions. No specific technical details about the vulnerability are provided beyond the vendor advisory. No known exploits in the wild have been reported.

CVE-2026-84142 is a moderate severity vulnerability involving internally found bugs in Firefox 154 that were fixed in Firefox 155. These bugs showed evidence of memory corruption or other security-relevant defects that could potentially be exploited with sufficient effort. The vulnerability affects multiple specific versions of the mozjs52 package as used in various Ubuntu LTS releases. No known exploits are reported in the wild. The vulnerability was addressed by Mozilla in Firefox 155.

CVE-2026-84143 is a high severity vulnerability involving internally found bugs in Firefox 154 and related ESR versions. These bugs include memory corruption or other security-relevant defects that could potentially be exploited. The vulnerability was fixed in Firefox 155 and corresponding ESR releases. The affected product versions include multiple specific Ubuntu package versions of mozjs52, which is part of the Firefox JavaScript engine. No detailed technical description is provided beyond the vendor advisory. The CVSS score is 9.8, indicating critical impact on confidentiality, integrity, and availability.