CVE-2026-39938

Cacti: Unauthenticated RCE on Graph Image

9.8 CriticalPublic exploitFix available

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior have unauthenticated LFI through graph_theme and rrdtool IPC serialization hardening. This issue has been resolved in version 1.2.31.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

0.69%Up 0.3 points since Jun 25, 2026

What each source reports

CVE List Score used 9.8

Cacti: Unauthenticated RCE on Graph Image

Record: CVE-2026-39938
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-22, CWE-78
Updated: 2026-11-02

EUVDEUVD-2026-39136 9.8

Record: EUVD-2026-39136
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

NVD 9.8

Record: CVE-2026-39938
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-22, CWE-78
Updated: 2026-11-02

OSV 9.8

Cacti: Unauthenticated RCE on Graph Image

Record: CVE-2026-39938
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-22, CWE-78
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-39938 9.8

Record: DEBIAN-CVE-2026-39938
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-39938 9.8

Record: UBUNTU-CVE-2026-39938
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-04

Affected products

cacti

Affected packages

Affected packages
Package	Affected	Fixed
`cacti` Debian:12	All versions, plus listed versions 1.2.24+ds1-11.2.24+ds1-1+deb12u11.2.24+ds1-1+deb12u21.2.24+ds1-1+deb12u31.2.24+ds1-1+deb12u4 Show 17 moreShow less 1.2.24+ds1-1+deb12u51.2.25+ds1-11.2.25+ds1-21.2.26+ds1-11.2.27+ds1-11.2.27+ds1-21.2.28+ds1-11.2.28+ds1-21.2.28+ds1-31.2.28+ds1-41.2.30+ds1-11.2.30+ds1-21.2.30+ds1-31.2.31+ds1-11.2.31+ds1-21.2.31+ds1-31.2.31+ds1-4	None known
`cacti` Debian:13	All versions, plus listed versions 1.2.30+ds1-11.2.30+ds1-21.2.30+ds1-31.2.31+ds1-11.2.31+ds1-21.2.31+ds1-31.2.31+ds1-4	None known
`cacti` Debian:14	before 1.2.31+ds1-1, plus listed versions 1.2.30+ds1-11.2.30+ds1-21.2.30+ds1-3	1.2.31+ds1-1
`cacti` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 1.1.18+ds1-11.1.27+ds1-21.1.27+ds1-31.1.28+ds1-21.1.35+ds1-1 Show 5 moreShow less 1.1.36+ds1-11.1.38+ds1-11.1.38+ds1-1ubuntu0.1~esm11.1.38+ds1-1ubuntu0.1~esm31.1.38+ds1-1ubuntu0.1~esm4	None known
`cacti` Ubuntu:Pro:20.04:LTS	All versions, plus listed versions 1.2.4+ds1-2ubuntu31.2.9+ds1-1ubuntu11.2.9+ds1-1ubuntu21.2.10+ds1-1ubuntu11.2.10+ds1-1ubuntu1+esm11.2.10+ds1-1ubuntu1.11.2.10+ds1-1ubuntu1.1+esm11.2.10+ds1-1ubuntu1.1+esm2	None known
`cacti` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 1.2.16+ds1-2ubuntu11.2.19+ds1-2ubuntu11.2.19+ds1-2ubuntu1+esm11.2.19+ds1-2ubuntu1.11.2.19+ds1-2ubuntu1.1+esm11.2.19+ds1-2ubuntu1.1+esm2	None known
`cacti` Ubuntu:24.04:LTS	All versions, plus listed versions 1.2.25+ds1-21.2.26+ds1-11.2.26+ds1-1ubuntu0.1	None known
`cacti` Ubuntu:25.10	All versions, plus listed versions 1.2.28+ds1-4ubuntu11.2.30+ds1-1ubuntu1	None known
`cacti` Ubuntu:26.10	All versions, plus listed versions 1.2.30+ds1-1ubuntu21.2.30+ds1-1ubuntu31.2.31+ds1-3ubuntu2	None known
`cacti` Ubuntu:26.04:LTS	All versions, plus listed versions 1.2.30+ds1-1ubuntu11.2.30+ds1-1ubuntu2	None known

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	kx00007/CVE-2026-39938	2026-04-04
PoC in GitHub	Polosss/By-Poloss..-..CVE-2026-39938	2026-06-26

History

History
Recorded	Changed	Sources
Nov 4, 2026	affected, exploits, facts	OSV
Nov 2, 2026	first indexed	CVE List, EUVD, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-39938 is a critical vulnerability (CVSS 9.8) in Cacti, published June 24, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.69%, the 53rd percentile. Fixed in cacti 1.2.31+ds1-1.