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OpenAdvisories
High ALSA-2025:1066 8 CVEs

Important: firefox security update

Published Feb 5, 2025 · Updated Oct 29, 2026

Ecosystem: AlmaLinux

Summary

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

Security Fix(es):

* firefox: thunderbird: Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7 (CVE-2025-1017)
* firefox: thunderbird: Use-after-free in Custom Highlight (CVE-2025-1010)
* firefox: thunderbird: Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 115.20, and Thunderbird 128.7 (CVE-2025-1016)
* firefox: thunderbird: Potential opening of private browsing tabs in normal browsing windows (CVE-2025-1013)
* firefox: thunderbird: A bug in WebAssembly code generation could result in a crash (CVE-2025-1011)
* firefox: thunderbird: Use-after-free in XSLT (CVE-2025-1009)
* firefox: thunderbird: Certificate length was not properly checked (CVE-2025-1014)
* firefox: thunderbird: Use-after-free during concurrent delazification (CVE-2025-1012)

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.

Fixed packages 2

ReleasePackageFixed in
AlmaLinux · 9 firefox 128.7.0-1.el9_5
AlmaLinux · 9 firefox-x11 128.7.0-1.el9_5

Vulnerabilities 8

  • Critical 9.8
    CVE-2025-1009

    Use-after-free in XSLT

    An attacker could have caused a use-after-free via crafted XSLT data, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Critical 9.8
    CVE-2025-1010

    Use-after-free in Custom Highlight

    An attacker could have caused a use-after-free via the Custom Highlight API, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Critical 9.8
    CVE-2025-1011

    A bug in WebAssembly code generation could result in a crash

    A bug in WebAssembly code generation could have lead to a crash. It may have been possible for an attacker to leverage this to achieve code execution. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Critical 9.8
    CVE-2025-1012

    Use-after-free during concurrent delazification

    A race during concurrent delazification could have led to a use-after-free. This vulnerability was fixed in Firefox 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Critical 9.8
    CVE-2025-1016

    Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 115.20, and Thunderbird 128.7

    Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 115.19, Firefox ESR 128.6, Thunderbird 115.19, and Thunderbird 128.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could ha…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Critical 9.8
    CVE-2025-1017

    Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7

    Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • High 8.8
    CVE-2025-1014

    Certificate length was not properly checked

    Certificate length was not properly checked when added to a certificate store. In practice only trusted data was processed. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 6.5
    CVE-2025-1013

    Potential opening of private browsing tabs in normal browsing windows

    A race condition could have led to private browsing tabs being opened in normal browsing windows. This could have resulted in a potential privacy leak. This vulnerability was fixed in Firefox 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi

References

  • report
    https://access.redhat.com/security/cve/CVE-2025-1009
  • report
    https://access.redhat.com/security/cve/CVE-2025-1010
  • report
    https://access.redhat.com/security/cve/CVE-2025-1011
  • report
    https://access.redhat.com/security/cve/CVE-2025-1012
  • report
    https://access.redhat.com/security/cve/CVE-2025-1013
  • report
    https://access.redhat.com/security/cve/CVE-2025-1014
  • report
    https://access.redhat.com/security/cve/CVE-2025-1016
  • report
    https://access.redhat.com/security/cve/CVE-2025-1017
  • report
    https://bugzilla.redhat.com/2343748
  • report
    https://bugzilla.redhat.com/2343750
  • report
    https://bugzilla.redhat.com/2343752
  • report
    https://bugzilla.redhat.com/2343754
  • report
    https://bugzilla.redhat.com/2343756
  • report
    https://bugzilla.redhat.com/2343760
  • report
    https://bugzilla.redhat.com/2343764
  • report
    https://bugzilla.redhat.com/2343765
  • advisory
    https://errata.almalinux.org/9/ALSA-2025-1066.html