CVE-2026-39894: Cacti: RRDtool metric shift via LC_NUMERIC locale comma decimal formatting
Cacti · cacti
Affected: cacti · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 3% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Cacti · cacti< 1.2.31
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
CoverageNo articles yet
No CyberSIXT article names CVE-2026-39894 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.