Similar to CVE-2023-28163, this time when choosing 'Save Link As', suggested filenames containing environment variable names would have resolved those in the context of the current user. *This bug only affects Firefox and Thunderbird on Windows. Other versions of Firefox and Thunderbird are unaffected.* This vulnerability affects Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
https://www.mozilla.org/security/advisories/mfsa2023-15/
https://www.mozilla.org/security/advisories/mfsa2023-14/