Red Hat alert RHSA-2026:8459-01 (thunderbird)

An update for thunderbird is now available for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of
Important. A Common Vulnerability Scoring System (CVSS) base score, which
gives a detailed severity rating, is available for each vulnerability from
the CVE link(s) in the References section.

Mozilla Thunderbird is a standalone mail and newsgroup client.

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.

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Original: https://access.redhat.com/security/data/csaf/v2/advisories/2026/rhsa-2026_8459.json