{"id":"CVE-2026-39894","summary":"Cacti: RRDtool metric shift via LC_NUMERIC locale comma decimal formatting","details":"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.","aliases":["GHSA-23g4-vf2j-94w4"],"modified":"2026-07-15T01:49:08.675007351Z","published":"2026-06-24T21:55:49.857Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-474"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39894.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39894.json"},{"type":"ADVISORY","url":"https://github.com/Cacti/cacti/security/advisories/GHSA-23g4-vf2j-94w4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39894"},{"type":"REPORT","url":"https://github.com/Cacti/cacti/issues/7011"},{"type":"FIX","url":"https://github.com/Cacti/cacti/commit/d2a698854956e9e4e53da9eab5b5719ae40e6893"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/cacti/cacti","events":[{"introduced":"0"},{"fixed":"1e8eaca26b84b128c39ce8cc8ece42d7ff76aac1"},{"fixed":"d2a698854956e9e4e53da9eab5b5719ae40e6893"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.2.31"}],"source":["CPE_RANGE","REFERENCES"],"cpe":"cpe:2.3:a:cacti:cacti:*:*:*:*:*:*:*:*"}}],"versions":["release/1.2.30","release/1.2.29","release/1.2.28","release/1.2.27","release/1.2.26","release/1.2.25","release/1.2.24","release/1.2.23","release/1.2.22","release/1.2.21","release/1.2.20","release/1.2.19","releaes/1.2.19","release/1.2.18","release/1.2.17","release/1.2.16","release/1.2.15","release/1.2.14","release/1.2.13","release/1.2.12","release/1.2.11","release/1.2.10","release/1.2.9","release/1.2.8","release/1.2.7","release/1.2.6","release/1.2.5","release/1.2.4","release/1.2.3","release/1.2.2","release/1.2.1","release/1.2.0","release/1.1.38","release/1.1.37","release/1.1.36","release/1.1.35","release/1.1.34","release/1.1.33","release/1.1.32","release/1.1.31","release/1.1.30","release/1.1.29","release/1.1.28","release/1.1.27","release/1.1.26","release/1.1.25","release/1.1.24","release/1.1.23","release/1.1.22","release/1.1.21","release/1.1.20","release/1.1.19","release/1.1.18","release/1.1.17","release/1.1.16","release/1.1.15","release/1.1.14","release/1.1.13","release/1.1.12","release/1.1.11","release/1.1.8","release/1.1.7","release/1.1.6","release/1.1.5","release/1.1.4","release/1.1.3","release/1.1.2","release/1.1.1","release/1.1.0","release/1.0.6","release/1.0.5","release/1.0.4","release/1.0.3","release/1.0.2","release/1.0.1","release/1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39894.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N"}]}