Allowed UNC hostnames for attachments interpreted as a regular expression (Mozilla Thunderbird)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.42 % · percentile 36 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- mozilla
- NVD status
- Analyzed
Description
The values of the mail.allowed_attachment_hostnames advanced config setting were used in a regular expression without escaping. For some possible valid hostnames, this could allow certain unintended hostnames to also match and serve remote attachments. This vulnerability was fixed in Thunderbird 155 and Thunderbird 153.2.
Weaknesses (CWE)
- CWE-1333 — Inefficient Regular Expression Complexity
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | CISA-ADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-69711
- GCVE · GCVE-0-2026-84642
CERT-FR advisories
- CERTFR-2026-AVI-1106 — Multiples vulnérabilités dans les produits Mozilla · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*< 153.2.0cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*≥ 154.0 < 155.0
Affected products
| Product | Versions |
|---|---|
| Mozilla · Thunderbird | unaffected 153.2 ≤ 153.* ; unaffected 155 ≤ * |
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 |