Mrtg: mrtg daemon symlink-following chown allows local privilege escalation via pid file path manipulation
Summary
| CVE | CVE-2026-72694 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-11 09:17:14 UTC |
| Updated | 2026-08-11 09:17:14 UTC |
| Description | A flaw was found in MRTG. When the MRTG daemon is started as a root user and subsequently drops privileges, a local, low-privileged attacker can exploit a symbolic link (symlink) following vulnerability. By influencing or pre-placing a symlink in the process ID (PID) file path, the attacker can trick the root process into changing the ownership of an arbitrary existing file to the daemon user. This can lead to local privilege escalation, allowing unauthorized access to or modification of sensitive files. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Problem Types: CWE-59 | CWE-59 Improper Link Resolution Before File Access ('Link Following')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 7.1 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
| 3.1 | CNA | CVSS | 7.1 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N |
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-72694 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: This issue was discovered by Found by AISLE in partnership with Red Hat. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-04-23T00:57:22.000Z | Reported to Red Hat. |
| CNA | 2026-08-11T07:28:48.463Z | Made public. |
Workarounds
CNA: To mitigate this issue, avoid starting the MRTG daemon as root with the `--daemon` option. Instead, configure MRTG to run directly as an unprivileged user. If root startup is strictly necessary, ensure that the PID file and its directory are owned by root and are not writable by unprivileged users, and prevent untrusted users from influencing the `--pid-file` path. Changes to service configuration may require a service restart to take effect.