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OpenAdvisories
High ALSA-2025:10074 4 CVEs

Important: firefox security update

Published Jul 1, 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: Content-Disposition header ignored when a file is included in an embed or object tag (CVE-2025-6430)
* firefox: Use-after-free in FontFaceSet (CVE-2025-6424)
* firefox: Incorrect parsing of URLs could have allowed embedding of youtube.com (CVE-2025-6429)
* firefox: The WebCompat WebExtension shipped with Firefox exposed a persistent UUID (CVE-2025-6425)

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 1

ReleasePackageFixed in
AlmaLinux · 8 firefox 128.12.0-1.el8_10.alma.1

Vulnerabilities 4

  • Critical 9.8
    CVE-2025-6424

    Use-after-free in FontFaceSet

    A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability was fixed in Firefox 140, Firefox ESR 115.25, Firefox ESR 128.12, Thunderbird 140, and Thunderbird 128.12.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 6.5
    CVE-2025-6429

    Incorrect parsing of URLs could have allowed embedding of youtube.com

    Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerabi…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 6.1
    CVE-2025-6430

    Content-Disposition header ignored when a file is included in an embed or object tag

    When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `<embed>` or `<object>` tag, potentially making a website vulnerable to a cross-site scripting attack. This vuln…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 4.3
    CVE-2025-6425

    The WebCompat WebExtension shipped with Firefox exposed a persistent UUID

    An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability was fixed in Firefox 1…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi

References

  • report
    https://access.redhat.com/security/cve/CVE-2025-6424
  • report
    https://access.redhat.com/security/cve/CVE-2025-6425
  • report
    https://access.redhat.com/security/cve/CVE-2025-6429
  • report
    https://access.redhat.com/security/cve/CVE-2025-6430
  • report
    https://bugzilla.redhat.com/2374555
  • report
    https://bugzilla.redhat.com/2374559
  • report
    https://bugzilla.redhat.com/2374561
  • report
    https://bugzilla.redhat.com/2374562
  • advisory
    https://errata.almalinux.org/8/ALSA-2025-10074.html