Red Hat Security Advisory: firefox security update
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in a Red Hat security update for Red Hat Enterprise Linux 9.4. The issues include privilege escalation in the Firefox Updater, unsafe attribute access during XPath parsing, process isolation bypass via "javascript:" URI links in cross-origin frames, and several memory safety bugs. These vulnerabilities have been fixed in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10 packages provided by Red Hat. The update is rated as Important by Red Hat Product Security.
AI Analysis
Technical Summary
This Red Hat security advisory addresses five vulnerabilities in Mozilla Firefox and Thunderbird, including CVE-2025-2817 (privilege escalation in Firefox Updater), CVE-2025-4087 (unsafe attribute access during XPath parsing), CVE-2025-4083 (process isolation bypass using "javascript:" URI links in cross-origin frames), and two memory safety bugs (CVE-2025-4091 and CVE-2025-4093). These issues affect Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. The advisory provides updated packages for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants to fix these vulnerabilities.
Potential Impact
The vulnerabilities include privilege escalation, unsafe attribute access, process isolation bypass, and memory safety issues, which could potentially allow attackers to escalate privileges, bypass security boundaries, or cause memory corruption. The severity is rated as important by Red Hat, indicating a significant security impact if exploited. No known exploits in the wild have been reported at the time of the advisory.
Mitigation Recommendations
Red Hat has released updated Firefox and Thunderbird packages for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants that address these vulnerabilities. Users should apply the provided security updates as detailed in the Red Hat advisory (RHSA-2025:4756) and the update instructions at https://access.redhat.com/articles/11258. Applying these updates will remediate the security issues. No additional mitigation steps are indicated by the vendor.
Red Hat Security Advisory: firefox security update
Description
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in a Red Hat security update for Red Hat Enterprise Linux 9.4. The issues include privilege escalation in the Firefox Updater, unsafe attribute access during XPath parsing, process isolation bypass via "javascript:" URI links in cross-origin frames, and several memory safety bugs. These vulnerabilities have been fixed in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10 packages provided by Red Hat. The update is rated as Important by Red Hat Product Security.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This Red Hat security advisory addresses five vulnerabilities in Mozilla Firefox and Thunderbird, including CVE-2025-2817 (privilege escalation in Firefox Updater), CVE-2025-4087 (unsafe attribute access during XPath parsing), CVE-2025-4083 (process isolation bypass using "javascript:" URI links in cross-origin frames), and two memory safety bugs (CVE-2025-4091 and CVE-2025-4093). These issues affect Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. The advisory provides updated packages for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants to fix these vulnerabilities.
Potential Impact
The vulnerabilities include privilege escalation, unsafe attribute access, process isolation bypass, and memory safety issues, which could potentially allow attackers to escalate privileges, bypass security boundaries, or cause memory corruption. The severity is rated as important by Red Hat, indicating a significant security impact if exploited. No known exploits in the wild have been reported at the time of the advisory.
Mitigation Recommendations
Red Hat has released updated Firefox and Thunderbird packages for Red Hat Enterprise Linux 9.4 Extended Update Support and related variants that address these vulnerabilities. Users should apply the provided security updates as detailed in the Red Hat advisory (RHSA-2025:4756) and the update instructions at https://access.redhat.com/articles/11258. Applying these updates will remediate the security issues. No additional mitigation steps are indicated by the vendor.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2025:4756
- Cve Count
- 5
- Additional Cves
- ["CVE-2025-4083","CVE-2025-4087","CVE-2025-4091","CVE-2025-4093"]
- Cvss Version
- null
Threat ID: 6a4049ea27e9c79719836454
Added to database: 06/27/2026, 22:08:42 UTC
Last enriched: 06/27/2026, 22:39:27 UTC
Last updated: 06/28/2026, 00:51:09 UTC
Views: 2
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