Security Vulnerabilities fixed in Thunderbird 154 — Mozilla

🗓️ 18 Aug 2026 00:00:00Reported by Mozilla FoundationType

mozilla🔗 www.mozilla.org👁 10 Views

Thunderbird 154 fixes internal memory corruption bugs in ESR 140.13, ESR 153.0 and 153.

Reporter	Title	Published	Views	Family All 541
GithubExploit	Exploit for Improper Isolation or Compartmentalization in Mozilla Firefox	25 Aug 202612:53	–	githubexploit
GithubExploit	Exploit for Improper Isolation or Compartmentalization in Mozilla Firefox	25 Aug 202600:27	–	githubexploit
GithubExploit	Exploit for Use After Free in Mozilla Firefox	27 Aug 202620:13	–	githubexploit
GithubExploit	Exploit for Improper Privilege Management in Mozilla Firefox	24 Aug 202620:07	–	githubexploit
Tenable Nessus	Amazon Linux 2023 : firefox (ALAS2023-2026-2105)	31 Aug 202600:00	–	nessus
Tenable Nessus	Amazon Linux 2 : thunderbird, --advisory ALAS2-2026-3880 (ALAS-2026-3880)	31 Aug 202600:00	–	nessus
Tenable Nessus	Amazon Linux 2 : firefox, --advisory ALAS2FIREFOX-2026-064 (ALASFIREFOX-2026-064)	31 Aug 202600:00	–	nessus
Tenable Nessus	AlmaLinux 9 : firefox (ALSA-2026:58897)	26 Aug 202600:00	–	nessus
Tenable Nessus	AlmaLinux 8 : firefox (ALSA-2026:58898)	26 Aug 202600:00	–	nessus
Tenable Nessus	AlmaLinux 10 : firefox (ALSA-2026:58899)	26 Aug 202600:00	–	nessus

Vulners

Node

mozilla thunderbirdRange<154

Source	Link
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/buglist.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi
bugzilla	www.bugzilla.mozilla.org/buglist.cgi
bugzilla	www.bugzilla.mozilla.org/show_bug.cgi

18 Aug 2026 00:00Current

5.9Medium risk

Vulners AI Score5.9

CVSS 3.19.8 - 10

EPSS0.00455

SSVC

Thunderbird memory corruption ESR 140.13 ESR 153.0 Thunderbird 153 security fixes