Vulnerability Description
Cacti is an open source performance and fault management framework. In versions 1.2.30 and below, the locale-dependent decimal formatting in rrdtool_function_update() can corrupt RRDtool metric values. The rrdtool_function_update() function checks metric values with is_numeric() and concatenates them into the RRDtool update command via PHP string interpolation. PHP's string cast of floats is locale-sensitive: if LC_NUMERIC uses comma as decimal separator (e.g., de_DE), a value of 1.5 becomes "1,5". RRDtool expects . as decimal separator, causing metric data to shift into wrong columns or be silently dropped. No setlocale() reset is present in the update path. This causes a data integrity issue, but is not remotely exploitable; it requires server locale misconfiguration. The issue has been fixed in version 1.2.31.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cacti | Cacti | < 1.2.31 |
Related Weaknesses (CWE)
References
- https://github.com/Cacti/cacti/commit/d2a698854956e9e4e53da9eab5b5719ae40e6893Patch
- https://github.com/Cacti/cacti/issues/7011Issue TrackingPatch
- https://github.com/Cacti/cacti/security/advisories/GHSA-23g4-vf2j-94w4Vendor Advisory
FAQ
What is CVE-2026-39894?
CVE-2026-39894 is a vulnerability with a CVSS score of 2.9 (LOW). Cacti is an open source performance and fault management framework. In versions 1.2.30 and below, the locale-dependent decimal formatting in rrdtool_function_update() can corrupt RRDtool metric values...
How severe is CVE-2026-39894?
CVE-2026-39894 has been rated LOW with a CVSS base score of 2.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-39894?
Check the references section above for vendor advisories and patch information. Affected products include: Cacti Cacti.