https://seclists.org/oss-sec/2026/q3/845: rsyslog: mmpstrucdata denial of service fixed in 8.2606.0
Affected Software
Frequently Asked Questions
Which deployments are exposed to this denial of service?
Deployments are affected only if they use the mmpstrucdata module to parse RFC 5424 structured data and accept messages large enough to contain an oversized parameter value. The module is not enabled by default.
What must an attacker do to trigger the issue?
An attacker must send a crafted message containing an oversized structured-data parameter value to an affected rsyslog instance. In affected versions, this can terminate rsyslogd.
What should operators do if they cannot immediately upgrade?
Limit acceptance of messages large enough to carry oversized structured-data parameter values, or avoid using mmpstrucdata to parse RFC 5424 structured data until a fixed or backported package is deployed. Distribution package users should check their distribution's security advisory or package changelog for backported fixes.
Does this issue provide code execution?
No code execution has been demonstrated or claimed. The reported impact is termination of rsyslogd.