CVE catalog
CVE-2026-48693
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 li
- Severity
- Medium · CVSS 5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.13% · Oct 25, 2026
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).
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | fastnetmon | sid | 1.2.9-1 | vulnerable |
| Debian | fastnetmon | forky | 1.2.9-1 | vulnerable |
| Debian | fastnetmon | trixie | 1.2.9-0+deb13u1 | vulnerable |
| Debian | fastnetmon | trixie-security | 1.2.9-0+deb13u1 | vulnerable |
| Debian | fastnetmon | bookworm | 1.2.4-2+deb12u1 | vulnerable |
| Debian | fastnetmon | bookworm-security | 1.2.4-2+deb12u1 | vulnerable |
| Cpe | fastnetmon | Not reported | Not reported | vulnerable |
| Cpe | fastnetmon | Not reported | Not reported | unknown |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | fastnetmon | source | sid | (unfixed) | unimportant | Not reported | Not reported |
| Debian | fastnetmon | source | forky | (unfixed) | unimportant | Not reported | Not reported |
| Debian | fastnetmon | source | trixie | (unfixed) | unimportant | Not reported | Not reported |
| Debian | fastnetmon | source | bookworm | (unfixed) | unimportant | Not reported | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [fastnetmon]Affected
Details (6)
1.2.4-2+deb12u1· amd64 · bookwormAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.4-2+deb12u1· arm64 · bookwormAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.8-1~bpo12+1· amd64 · bookworm-backportsAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.8-1~bpo12+1· arm64 · bookworm-backportsAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.4-2+deb12u1· amd64 · bookworm-securityAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
1.2.4-2+deb12u1· arm64 · bookworm-securityAffected
nvd · fastnetmon · debian · bookworm; nvd · fastnetmon · debian · 12
[Debian 13 (Trixie)]
- [fastnetmon]Affected
Details (4)
1.2.9-0+deb13u1· amd64 · trixieAffected
nvd · fastnetmon · debian · 13
1.2.9-0+deb13u1· arm64 · trixieAffected
nvd · fastnetmon · debian · 13
1.2.9-0+deb13u1· amd64 · trixie-securityAffected
nvd · fastnetmon · debian · 13
1.2.9-0+deb13u1· arm64 · trixie-securityAffected
nvd · fastnetmon · debian · 13
Observed:
References
- [https://nvd.nist.gov/vuln/detail/CVE-2026-48693]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-48693]
- [https://security-tracker.debian.org/tracker/CVE-2026-48693]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48693.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]