CVE-2025-34274: Nagios Log Server · Execution with Unnecessary Privileges
Affects Nagios Log ServerSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 2.0% chance of exploitation in 30 days – higher than 81% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Nagios Log Server | Affected
| Fixed in– |
AI-suggested
To mitigate this vulnerability, European organizations should immediately upgrade Nagios Log Server to version 2024R2.0.3 or later, where the Logstash process runs under the 'nagios' user instead of root. Prior to upgrading, audit all Logstash plugins and pipeline configurations to identify and remove insecure or unnecessary components that could be exploited. Implement strict access controls and network segmentation to limit exposure of the Logstash service to trusted networks only. Employ application whitelisting and runtime monitoring to detect anomalous Logstash behavior. Regularly review and apply security patches for all components of the logging infrastructure. Additionally, conduct penetration testing and vulnerability assessments focused on Logstash configurations. Consider deploying host-based intrusion detection systems (HIDS) to monitor for unauthorized privilege escalations. Finally, ensure comprehensive logging and alerting are in place to detect exploitation attempts promptly.
Description
CVE-2025-34274 is a critical vulnerability in Nagios Log Server versions prior to 2024R2.0.3 where the embedded Logstash process runs with root privileges. An attacker exploiting this flaw via insecure plugins, pipeline configuration injection, or input parsing vulnerabilities could execute arbitrary code with root access, leading to full system compromise. The vulnerability arises from execution with unnecessary privileges (CWE-250). Nagios has mitigated this risk in newer versions by running Logstash under a lower-privileged 'nagios' user. The CVSS 4.0 score is 9.3, reflecting the high impact and ease of exploitation without authentication or user interaction. European organizations using affected Nagios Log Server versions face significant risks, especially critical infrastructure and enterprises relying on this logging solution.