Red Hat Security Advisory: thunderbird security update
Affects Red Hat thunderbirdSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.8 Critical · fixed in Red Hat package updates : patch Red Hat thunderbird as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 115.34.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 7 Apr 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 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Product Security Red Hat | Affected
| Fixed in– |
AI-suggested
Red Hat has released updated Thunderbird packages for Red Hat Enterprise Linux 8.4 that address these vulnerabilities. Users should apply the security update as described in the Red Hat advisory RHSA-2026:14303 and the referenced article https://access.redhat.com/articles/11258. No additional mitigations are specified or required beyond applying the official update.
Description
This update for MozillaFirefox fixes the following issues: Update to Firefox Extended Support Release 140.9.1 ESR (bsc#1261663). - MFSA 2026-27: * CVE-2026-5731: 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-2026-5732: incorrect boundary conditions, integer overflow in the Graphics: Text component. * CVE-2026-5734: memory safety bugs fixed in Firefox ESR 140.9.1, Thunderbird ESR 140.9.1, Firefox 149.0.2 and Thunderbird 149.0.2.
References
- access.redhat.com/errata/RHSA-2026:14303 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2451805 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2451819 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2455897 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2455901 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2455908 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_14303.json (opens in a new tab)
- suse.com/support/security/rating/ (opens in a new tab)
- ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_20486-1.json (opens in a new tab)
- bugzilla.suse.com/1261663 (opens in a new tab)
- suse.com/security/cve/CVE-2026-5731/ (opens in a new tab)
- suse.com/security/cve/CVE-2026-5732/ (opens in a new tab)
- suse.com/security/cve/CVE-2026-5734/ (opens in a new tab)