Mozjs52: Thunderbird's check that prevents mailbox: URLs from accessing files on remote Windows network shares could
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in 153.6 : patch mozjs52 soon.
Data as of 6 Nov 2026, 05:05 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 8.1 |
|---|
- Patch
- Available – fixed in 153.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Oct 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 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmozjs115pkg:deb/ubuntu/mozjs115?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs78pkg:deb/ubuntu/mozjs78?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs91pkg:deb/ubuntu/mozjs91?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=jammyOther threats | 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
This vulnerability has been fixed in Thunderbird versions 153.6 and 159. Users and administrators should update Thunderbird to version 153.6 or later to remediate this issue. No additional mitigation actions are required once the update is applied.
Description
A vulnerability in Thunderbird on Windows allows bypassing the check that prevents mailbox: URLs from accessing files on remote Windows network shares by using extended-length UNC paths. This can cause Thunderbird to connect to an attacker-controlled SMB server, leaking the user's Windows account name and NTLM authentication data. The leaked NTLM data could be used for offline password cracking or relay attacks. The issue affects only Thunderbird on Windows and was fixed in Thunderbird versions 153.6 and 159.
References
- ubuntu.com/security/CVE-2026-118176 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-118176 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-122/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=2081141 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-121/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-122/ (opens in a new tab)