{"id":"CVE-2026-48693","details":"FastNetMon Community Edition through 1.2.9 is vulnerable to a local symlink attack via predictable file paths in /tmp. The statistics file path defaults to '/tmp/fastnetmon.dat' (src/fastnetmon.cpp line 159). The print_screen_contents_into_file() function (src/fastnetmon_logic.cpp line 2186) opens this path with std::ios::trunc without checking for symlinks or using O_NOFOLLOW. Additionally, the chmod() call on line 2190 always operates on cli_stats_file_path regardless of which file_path parameter was passed (a bug that applies wrong permissions), and the umask is set to 0 during daemonization (src/fastnetmon.cpp line 1821), making all created files world-writable. A local attacker can exploit this to overwrite arbitrary files as the FastNetMon process user (typically root).","modified":"2026-07-08T08:12:34.991239339Z","published":"2026-05-26T00:00:00Z","database_specific":{"cna_assigner":"mitre","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48693.json"},"references":[{"type":"WEB","url":"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon.cpp"},{"type":"WEB","url":"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/fastnetmon_logic.cpp"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48693.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48693"},{"type":"PACKAGE","url":"https://github.com/pavel-odintsov/fastnetmon"},{"type":"ARTICLE","url":"https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48693-symlink-tmp"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/pavel-odintsov/fastnetmon","events":[{"introduced":"0"},{"fixed":"394fbe06d112f9609d3d1cb10d60cbf98347c96a"}],"database_specific":{"source":["DESCRIPTION","CPE_RANGE"],"cpe":"cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"1.2.9"},{"last_affected":"1.2.9"}]}}],"versions":["v1.2.8","v1.2.7","v1.2.6","v1.2.5","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.9","v1.1.8","v1.1.7","v1.1.6","v1.1.5","v1.1.4","v1.1.3","v1.1.2","v1.1.0","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48693.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N"}]}