CVE-2026-118176
Bypass of remote UNC path restriction in mailbox: URLs
Not available
At a glance
- Source
- NVD
- EPSS
- EPSS 0.22 % · percentile 12 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- mozilla
- NVD status
- Received
Description
Thunderbird's check that prevents mailbox: URLs from accessing files on remote Windows network shares could be bypassed using extended-length UNC paths. Displaying a specially crafted email could cause Thunderbird to connect to an SMB server chosen by the attacker, disclosing the user's Windows account name and NTLM authentication data, which could be used for offline password cracking or relay attacks. This bug only affects Thunderbird on Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.
References
European references
- ENISA EUVD · EUVD-2026-111353
- GCVE · GCVE-0-2026-118176
CERT-FR advisories
- CERTFR-2026-AVI-1406 — Multiples vulnérabilités dans les produits Mozilla · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Mozilla · Thunderbird | unaffected 153.6 ≤ 153.* ; unaffected 159 ≤ * |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |