RHSA-2026:13533 — Security Advisory
Red Hat Security Advisory: thunderbird security update
Severity
ImportantRed Hat Product Security
Products
Official CSAF product identity
Published · May 5, 2026
Updated · October 31, 2026
Topic
An update for thunderbird is now available for Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions.
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.
Description
Mozilla Thunderbird is a standalone mail and newsgroup client.
Security Fix(es):
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libpng: libpng: Arbitrary code execution due to use-after-free vulnerability (CVE-2026-33416)
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libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion (CVE-2026-33636)
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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)
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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)
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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.