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OpenAdvisories
High ALSA-2026:7672 5 CVEs

Important: firefox security update

Published Apr 13, 2026 · 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):

* libpng: libpng: Arbitrary code execution due to use-after-free vulnerability (CVE-2026-33416)
* libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion (CVE-2026-33636)
* thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 (CVE-2026-5734)
* thunderbird: firefox: Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2 (CVE-2026-5731)
* firefox: thunderbird: Incorrect boundary conditions, integer overflow in the Graphics: Text component (CVE-2026-5732)

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 · 10 firefox 140.9.1-1.el10_1

Vulnerabilities 5

  • Critical 9.8
    CVE-2026-5731

    Memory safety bugs fixed in Firefox ESR 115.34.1, Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2

    Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have …

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • High 8.8
    CVE-2026-5732

    Incorrect boundary conditions, integer overflow in the Graphics: Text component

    Incorrect boundary conditions, integer overflow in the Graphics: Text component. This vulnerability was fixed in Firefox 149.0.2, Firefox ESR 140.9.1, Thunderbird 149.0.2, and Thunderbird 140.9.1.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • High 8.1
    CVE-2026-5734

    Memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2

    Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. 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 …

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • High 7.6
    CVE-2026-33636

    LIBPNG has ARM NEON Palette Expansion Out-of-Bounds Read on AArch64

    LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.6.36 through 1.6.55, an out-of-bounds read and write exists in libpng's ARM/AArch64 Neon-optimized palett…

    pnggroup libpng fltk libpng1.6 Debian Ubuntu Azure Linux Alpine Wolfi
  • High 7.5
    CVE-2026-33416

    LIBPNG has use-after-free via pointer aliasing in `png_set_tRNS` and `png_set_PLTE`

    LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_str…

    pnggroup libpng openjpeg2 fltk Debian Ubuntu Azure Linux Alpine Wolfi

References

  • report
    https://access.redhat.com/security/cve/CVE-2026-33416
  • report
    https://access.redhat.com/security/cve/CVE-2026-33636
  • report
    https://access.redhat.com/security/cve/CVE-2026-5731
  • report
    https://access.redhat.com/security/cve/CVE-2026-5732
  • report
    https://access.redhat.com/security/cve/CVE-2026-5734
  • report
    https://bugzilla.redhat.com/2451805
  • report
    https://bugzilla.redhat.com/2451819
  • report
    https://bugzilla.redhat.com/2455897
  • report
    https://bugzilla.redhat.com/2455901
  • report
    https://bugzilla.redhat.com/2455908
  • advisory
    https://errata.almalinux.org/10/ALSA-2026-7672.html