Unauthenticated code execution via graph_theme traversal
Published Jun 24, 2026 · Updated Jun 24, 2026
Path traversal in Cacti 1.2.30 and earlier allows remote attackers to read local files through unauthenticated graph image requests. The rrdtool_function_theme_font_options() function appends graph_theme beneath include/themes and loads the resulting rrdtheme.php path without rejecting traversal sequences. No account or user interaction is required; readable files can be exposed, and inclusion of a poisoned web-server log can execute code in the Cacti process.
Summary
What happened
Path traversal in Cacti 1.2.30 and earlier allows remote attackers to read local files through unauthenticated graph image requests. The rrdtool_function_theme_font_options() function appends graph_theme beneath include/themes and loads the resulting rrdtheme.php path without rejecting traversal sequences. No account or user interaction is required; readable files can be exposed, and inclusion of a poisoned web-server log can execute code in the Cacti process.
The record
- CVE
- CVE-2026-39938
- Published
- Jun 24, 2026
- Updated
- Jun 24, 2026
- Vendor
- The Cacti Group
- Product
- Cacti
- Classifications
- CWE-22, CWE-78, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 24, 2026CVE publishedPublication date reported by the CVE source.
- 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.
- Affected versionversion=< 1.2.31
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- By-Poloss CVE-2026-39938 proof of conceptproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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