Red Hat Security Advisory: thunderbird security update
Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Security Fix(es): * firefox: Incorrect boundary conditions in the JavaScript Engine: JIT component (CVE-2026-8388) * firefox: Other issue in the JavaScript Engine component (CVE-2026-8391) * firefox: Sandbox escape in the Profile Backup component (CVE-2026-8401) * firefox: Integer overflow in the Networking: JAR component (CVE-2026-8956) * firefox: Memory safety bugs fixed in Firefox ESR 115.36, Firefox ESR 140.11 and Firefox 151 (CVE-2026-8975) * firefox: Privilege escalation in the DOM: Workers component (CVE-2026-8955) * firefox: Denial-of-service due to invalid pointer in the Audio/Video: Web Codecs component (CVE-2026-8968) * firefox: Incorrect boundary conditions, integer overflow in the Audio/Video component (CVE-2026-8954) * firefox: Information disclosure, sandbox escape in the Security: Process Sandboxing component (CVE-2026-8958) * firefox: Incorrect boundary conditions in the Audio/Video: Web Codecs component (CVE-2026-8946) * firefox: Privilege escalation in the Security component (CVE-2026-8970) * firefox: Same-origin policy bypass in the Networking: HTTP component (CVE-2026-8950) * firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151 (CVE-2026-8974) * firefox: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-8953) * firefox: Spoofing issue in the Form Autofill component (CVE-2026-8961) * firefox: Use-after-free in the DOM: Bindings (WebIDL) component (CVE-2026-8947) * firefox: Mitigation bypass in the DOM: Security component (CVE-2026-8962) * firefox: Privilege escalation in the Enterprise Policies component (CVE-2026-8957) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
AI Analysis
Technical Summary
This Red Hat security advisory addresses multiple vulnerabilities in Mozilla Firefox, including CVE-2026-8388 and 17 additional CVEs. The issues span a wide range of components such as the JavaScript Engine JIT, Profile Backup, Networking JAR, DOM Workers, Audio/Video Web Codecs, Process Sandboxing, Security components, HTTP Networking, Disability Access APIs, Form Autofill, and Enterprise Policies. Vulnerabilities include incorrect boundary conditions, integer overflows, sandbox escapes, memory safety bugs, privilege escalations, denial-of-service, information disclosure, same-origin policy bypass, use-after-free, spoofing, and mitigation bypass. These flaws affect Firefox ESR 115.36, ESR 140.11, and Firefox 151 as packaged for Red Hat Enterprise Linux 9. The update is rated as important by Red Hat Product Security and addresses these issues with fixed package versions.
Potential Impact
The vulnerabilities collectively could allow attackers to escape sandbox restrictions, escalate privileges, cause denial-of-service conditions, disclose sensitive information, bypass same-origin policies, and perform spoofing attacks. Memory safety bugs and use-after-free issues increase the risk of arbitrary code execution or crashes. The impact severity is high due to the potential for privilege escalation and sandbox escapes, which could compromise system security and user data confidentiality.
Mitigation Recommendations
An official security update from Red Hat is available that addresses all listed vulnerabilities. Users of Red Hat Enterprise Linux 9 and related Extended Update Support versions should apply the updated Firefox packages (e.g., firefox-140.11.0-1.el9_8) as provided by Red Hat. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigation steps are required beyond applying the official patches.
Red Hat Security Advisory: thunderbird security update
Description
Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Security Fix(es): * firefox: Incorrect boundary conditions in the JavaScript Engine: JIT component (CVE-2026-8388) * firefox: Other issue in the JavaScript Engine component (CVE-2026-8391) * firefox: Sandbox escape in the Profile Backup component (CVE-2026-8401) * firefox: Integer overflow in the Networking: JAR component (CVE-2026-8956) * firefox: Memory safety bugs fixed in Firefox ESR 115.36, Firefox ESR 140.11 and Firefox 151 (CVE-2026-8975) * firefox: Privilege escalation in the DOM: Workers component (CVE-2026-8955) * firefox: Denial-of-service due to invalid pointer in the Audio/Video: Web Codecs component (CVE-2026-8968) * firefox: Incorrect boundary conditions, integer overflow in the Audio/Video component (CVE-2026-8954) * firefox: Information disclosure, sandbox escape in the Security: Process Sandboxing component (CVE-2026-8958) * firefox: Incorrect boundary conditions in the Audio/Video: Web Codecs component (CVE-2026-8946) * firefox: Privilege escalation in the Security component (CVE-2026-8970) * firefox: Same-origin policy bypass in the Networking: HTTP component (CVE-2026-8950) * firefox: Memory safety bugs fixed in Firefox ESR 140.11 and Firefox 151 (CVE-2026-8974) * firefox: Sandbox escape due to use-after-free in the Disability Access APIs component (CVE-2026-8953) * firefox: Spoofing issue in the Form Autofill component (CVE-2026-8961) * firefox: Use-after-free in the DOM: Bindings (WebIDL) component (CVE-2026-8947) * firefox: Mitigation bypass in the DOM: Security component (CVE-2026-8962) * firefox: Privilege escalation in the Enterprise Policies component (CVE-2026-8957) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This Red Hat security advisory addresses multiple vulnerabilities in Mozilla Firefox, including CVE-2026-8388 and 17 additional CVEs. The issues span a wide range of components such as the JavaScript Engine JIT, Profile Backup, Networking JAR, DOM Workers, Audio/Video Web Codecs, Process Sandboxing, Security components, HTTP Networking, Disability Access APIs, Form Autofill, and Enterprise Policies. Vulnerabilities include incorrect boundary conditions, integer overflows, sandbox escapes, memory safety bugs, privilege escalations, denial-of-service, information disclosure, same-origin policy bypass, use-after-free, spoofing, and mitigation bypass. These flaws affect Firefox ESR 115.36, ESR 140.11, and Firefox 151 as packaged for Red Hat Enterprise Linux 9. The update is rated as important by Red Hat Product Security and addresses these issues with fixed package versions.
Potential Impact
The vulnerabilities collectively could allow attackers to escape sandbox restrictions, escalate privileges, cause denial-of-service conditions, disclose sensitive information, bypass same-origin policies, and perform spoofing attacks. Memory safety bugs and use-after-free issues increase the risk of arbitrary code execution or crashes. The impact severity is high due to the potential for privilege escalation and sandbox escapes, which could compromise system security and user data confidentiality.
Mitigation Recommendations
An official security update from Red Hat is available that addresses all listed vulnerabilities. Users of Red Hat Enterprise Linux 9 and related Extended Update Support versions should apply the updated Firefox packages (e.g., firefox-140.11.0-1.el9_8) as provided by Red Hat. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigation steps are required beyond applying the official patches.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:21382
- Cve Count
- 18
- Additional Cves
- ["CVE-2026-8391","CVE-2026-8401","CVE-2026-8946","CVE-2026-8947","CVE-2026-8950","CVE-2026-8953","CVE-2026-8954","CVE-2026-8955","CVE-2026-8956","CVE-2026-8957","CVE-2026-8958","CVE-2026-8961","CVE-2026-8962","CVE-2026-8968","CVE-2026-8970","CVE-2026-8974","CVE-2026-8975"]
- Cvss Version
- null
Threat ID: 6a175ed2e29bf47b50ed8855
Added to database: 05/27/2026, 21:14:58 UTC
Last enriched: 06/23/2026, 17:06:16 UTC
Last updated: 07/31/2026, 19:23:00 UTC
Views: 57
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.