{"cve":"CVE-2025-5986","nvd":{"published":"2025-06-11T12:15:29.183","modified":"2026-06-17T09:49:09.570","status":"Modified","description":"A crafted HTML email using mailbox:/// links can trigger automatic, unsolicited downloads of .pdf files to the user's desktop or home directory without prompting, even if auto-saving is disabled. This behavior can be abused to fill the disk with garbage data (e.g. using /dev/urandom on Linux) or to leak Windows credentials via SMB links when the email is viewed in HTML mode. While user interaction is required to download the .pdf file, visual obfuscation can conceal the download trigger. Viewing the email in HTML mode is enough to load external content. This vulnerability was fixed in Thunderbird 128.11.1 and Thunderbird 139.0.2.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-451"],"references":["https://bugzilla.mozilla.org/buglist.cgi?bug_id=1958580%2C1968012","https://www.mozilla.org/security/advisories/mfsa2025-49/","https://www.mozilla.org/security/advisories/mfsa2025-50/","https://lists.debian.org/debian-lts-announce/2025/07/msg00002.html"],"products":["mozilla:thunderbird"],"source":"nvd","synced_at":"2026-10-19T22:02:23.998251710+00:00"},"epss":{"cve":"CVE-2025-5986","score":0.0058,"percentile":0.47704,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}