CVE-2021-3277
Nagios XI 5.7.5 and earlier allows authenticated admins to upload arbitrary files due to improper validation of the rename functionality in custom-includes component, which leads to remote code execution by uploading php files.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 59.0%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
Description
Nagios XI 5.7.5 and earlier allows authenticated admins to upload arbitrary files due to improper validation of the rename functionality in custom-includes component, which leads to remote code execution by uploading php files.
- CVSS 3.1
- 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 59.02% probability · 99th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-434
- Affected
- nagios/nagios xi
- Source
- cve@mitre.org
EPSS moved from 59.0% on 24 October 2026 to 59.0% on 3 November 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- https://asaf.me/2021/01/21/nagios-xi-5-7-5-remote-code-execution/Third Party Advisory
- https://asaf.me/2021/01/21/nagios-xi-5-7-5-remote-code-execution/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.