CVE-2026-39894

Metric corruption via locale-sensitive float serialization

Published Jun 24, 2026 · Updated Jun 24, 2026

Data corruption in Cacti 1.2.30 and earlier allows attackers to misplace or drop RRDtool metrics through a comma-decimal server locale. The rrdtool_function_update() poller path accepts numeric floats and appends their locale-sensitive PHP string casts directly to an RRDtool update command. Reachability requires the poller process to use an LC_NUMERIC locale that casts floats with commas; the bounded result is corrupted, shifted, or missing metric data.

CVSS severity2.9
Low
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Data corruption in Cacti 1.2.30 and earlier allows attackers to misplace or drop RRDtool metrics through a comma-decimal server locale. The rrdtool_function_update() poller path accepts numeric floats and appends their locale-sensitive PHP string casts directly to an RRDtool update command. Reachability requires the poller process to use an LC_NUMERIC locale that casts floats with commas; the bounded result is corrupted, shifted, or missing metric data.

The record

CVE
CVE-2026-39894
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Cacti Group
Product
Cacti
Classifications
CWE-474
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.2.31

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Cacti Group · Cactiversion=< 1.2.31

Published CVSS scores

2.5NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N
2.9GitHubCVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-474Use of Function with Inconsistent Implementations

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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