CVE-2026-72694: Mrtg: mrtg daemon symlink-following chown allows local privilege escalation via pid file path manipulation

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-11 · updated 2026-10-30
Weakness: CWE-59

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.

Affected products

Red Hat Enterprise Linux 10: all versions — fixed in 0:2.17.10-12.el10_2.1
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:2.17.10-11.el10_0.1
Red Hat Enterprise Linux 7: all versions
Red Hat Enterprise Linux 8: all versions — fixed in 0:2.17.7-1.el8_10.1
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 0:2.17.7-1.el8_4.1
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 0:2.17.7-1.el8_4.1
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:2.17.7-1.el8_6.1
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 0:2.17.7-1.el8_6.1
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:2.17.7-1.el8_8.1
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:2.17.7-1.el8_8.1
Red Hat Enterprise Linux 9: all versions — fixed in 0:2.17.7-12.el9_8.1
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:2.17.7-10.el9_2.1
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:2.17.7-11.el9_4.1
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:2.17.7-11.el9_6.1

How to fix

Upgrade to a fixed version: Red Hat Enterprise Linux 10 0:2.17.10-12.el10_2.1; Red Hat Enterprise Linux 10.0 Extended Update Support 0:2.17.10-11.el10_0.1; Red Hat Enterprise Linux 8 0:2.17.7-1.el8_10.1; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 0:2.17.7-1.el8_4.1; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 0:2.17.7-1.el8_4.1; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:2.17.7-1.el8_6.1; Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:2.17.7-1.el8_6.1; Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:2.17.7-1.el8_8.1; Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:2.17.7-1.el8_8.1; Red Hat Enterprise Linux 9 0:2.17.7-12.el9_8.1; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:2.17.7-10.el9_2.1; Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:2.17.7-11.el9_4.1. Check the vendor advisory for mitigations.

References

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