Skip to content
OpenAdvisories
Critical USN-7191-1 8 CVEs

firefox vulnerabilities

Published Jan 9, 2025 · Updated Apr 27, 2026

Ecosystem: Ubuntu

Summary

Multiple security issues were discovered in Firefox. If a user were
tricked into opening a specially crafted website, an attacker could
potentially exploit these to cause a denial of service, obtain sensitive
information across domains, or execute arbitrary code. (CVE-2025-0237,
CVE-2025-0239, CVE-2025-0240, CVE-2025-0242, CVE-2025-0243, CVE-2025-0247)

Irvan Kurniawan discovered that Firefox incorrectly handled memory when
breaking lines in text, leading to a use-after-free vulnerability. An
attacker could possibly use this issue to cause a denial of service or
possibly execute arbitrary code. (CVE-2025-0238)

Nils Bars discovered that Firefox incorrectly handled memory when using
JavaScript Text Segmentation. An attacker could possibly use this issue to
cause a denial of service. (CVE-2025-0241)

Fixed packages 1

ReleasePackageFixed in
Ubuntu · 20.04 LTS 20.04:LTS firefox 134.0+build1-0ubuntu0.20.04.1

Vulnerabilities 8

  • Critical 9.8
    CVE-2025-0247 EPSS 11%

    Memory safety bugs fixed in Firefox 134 and Thunderbird 134

    Memory safety bugs present in Firefox 133 and Thunderbird 133. 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. This vulnerability was fixed in Firefo…

    Mozilla Firefox Thunderbird thunderbird Browsers Ubuntu Wolfi
  • High 7.7
    CVE-2025-0241

    Memory corruption when using JavaScript Text Segmentation

    When segmenting specially crafted text, segmentation would corrupt memory leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 6.5
    CVE-2025-0242 EPSS 15%

    Memory safety bugs fixed in Firefox 134, Thunderbird 134, Firefox ESR 115.19, Firefox ESR 128.6, Thunderbird 115.19, and Thunderbird 128.6

    Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 115.18, Firefox ESR 128.5, Thunderbird 115.18, and Thunderbird 128.5. 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
  • Medium 5.4
    CVE-2025-0237

    WebChannel APIs susceptible to confused deputy attack

    The WebChannel API, which is used to transport various information across processes, did not check the sending principal but rather accepted the principal being sent. This could have led to privilege escalation attacks. This vulnerability was fixed in Firefox…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 5.3
    CVE-2025-0238

    Use-after-free when breaking lines in text

    Assuming a controlled failed memory allocation, an attacker could have caused a use-after-free, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Firefox ESR 115.19, Thunderbird 134, and Thunderbird 12…

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 5.1
    CVE-2025-0243

    Memory safety bugs fixed in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6

    Memory safety bugs present in Firefox 133, Thunderbird 133, Firefox ESR 128.5, and Thunderbird 128.5. 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
  • Medium 4.0
    CVE-2025-0239

    Alt-Svc ALPN validation failure when redirected

    When using Alt-Svc, ALPN did not properly validate certificates when the original server is redirecting to an insecure site. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi
  • Medium 4.0
    CVE-2025-0240

    Compartment mismatch when parsing JavaScript JSON module

    Parsing a JavaScript module as JSON could, under some circumstances, cause cross-compartment access, which may result in a use-after-free. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Thunderbird 134, and Thunderbird 128.6.

    Mozilla Firefox Thunderbird thunderbird Browsers Debian Ubuntu Wolfi

References

  • report
    https://ubuntu.com/security/CVE-2025-0237
  • report
    https://ubuntu.com/security/CVE-2025-0238
  • report
    https://ubuntu.com/security/CVE-2025-0239
  • report
    https://ubuntu.com/security/CVE-2025-0240
  • report
    https://ubuntu.com/security/CVE-2025-0241
  • report
    https://ubuntu.com/security/CVE-2025-0242
  • report
    https://ubuntu.com/security/CVE-2025-0243
  • report
    https://ubuntu.com/security/CVE-2025-0247