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CVE-2026-110249VulnerabilityPublished Updated

Thunderbird: A malicious, compromised, or MITM-controlled Exchange server can return a single well-formed SOAP

Affects thunderbirdSource GCVE Database

0
Authoritative record:CVE-2026-110249· High 8.6

Not known to be exploited · CVSS 8.6 High · fixed in 153.5 : patch thunderbird soon.

Data as of 28 Oct 2026, 23:44 UTC

CVSS 3.1 base score
8.6High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 153.5
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 13 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.10thunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=stonkingOther threatsAffected
  • =2:1snap1-0ubuntu5
Fixed in–
Ubuntu 26.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=resoluteOther threatsAffected
  • =2:1snap1-0ubuntu3
  • =2:1snap1-0ubuntu4
  • =2:1snap1-0ubuntu5
Fixed in–
Ubuntu 24.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=nobleOther threatsAffected
  • 1:115.3.1+build1-0ubuntu1 – 2:1snap1-0ubuntu3
14 affected builds
Fixed in–
Ubuntu 22.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=jammyOther threatsAffected
  • 1:91.1.2+build1-0ubuntu1 – 1:140.7.1+build1-0ubuntu0.22.04.1
39 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

This vulnerability has been fixed in Thunderbird versions 158 and 153.5. Users and administrators should upgrade to these or later versions to remediate the issue. No additional mitigation steps are required as the fix is available and addresses the vulnerability directly.

Description

A vulnerability in Thunderbird allows a malicious, compromised, or man-in-the-middle controlled Exchange server to send a specially crafted SOAP response with an element containing enough attributes to cause Thunderbird's main thread to become CPU-bound for a prolonged period, ranging from seconds to hours. This denial-of-service condition was addressed and fixed in Thunderbird versions 158 and 153.5.

References

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