CVE-2026-45186: thunderbird security, bug fix, and enhancement update
Affects thunderbirdSource GCVE Database
Not known to be exploited · CVSS 2.9 Low : upgrade to 153.5.0-1.el10_2.alma.1 when convenient.
Data as of 29 Oct 2026, 14:41 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 153.5.0-1.el10_2.alma.1
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:LExploitation evidence
Disclosed: evidence found.
CVE published 10 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade the AlmaLinux thunderbird package to 153.5.0-1.el10_2.alma.1.
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| AlmaLinux 10thunderbird | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A security update fixing this vulnerability is available in Thunderbird version 153.5.0-1.el10_2.alma.1 and later. Users and administrators should apply this update promptly to remediate the denial of service issue. Refer to the Red Hat advisory and update instructions at https://access.redhat.com/articles/11258 for detailed guidance.
Description
Mozilla Thunderbird contains a vulnerability in the libexpat XML parsing library that allows denial of service via crafted XML input (CVE-2026-45186). This security issue is addressed in Thunderbird version 153.5.0-1.el10_2.alma.1 and later. The update also includes bug fixes and enhancements related to the Thunderbird ESR 153 rebase for Red Hat Enterprise Linux 10.2 Extended Update Support.