Medium File handling exploit reference

CVE-2026-40084 — Cacti: Arbitrary File Read via Path Traversal in Report `format_file` Parameter

Cacti is an open source performance and fault management framework. Versions 1.2.30 and prior are vulnerable to Path Traversal through the Report format_file Parameter, causing arbitrary file read. This vulnerability occurs in two stages. In the first stage (stored injection), lib/html_reports.php at line 283 stores $save['format_file'] = $post['format_file'] directly into the database without any validation. In the second stage (file read), lib/reports.php at line 667 concatenates CACTI_PATH_FORMATS . '/' . $format_file, and line 670 then calls file($format_file), reading arbitrary files from the filesystem. This issue has been fixed in version 1.2.31.

Published Jun 25, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.5% (30-day exploitation probability)+6
Technical severity (medium)+3
CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.49%

ahead of 40% of scored CVEs · Oct 14, 2026

Affects

Cacti

CVSS base

6.5

Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)
Documented mitigation — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Cacti Cacti).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (file handling), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Cacti	Cacti	< 1.2.31	Vulnerable	NIST National Vulnerability Database
Cacti	Cacti	version < 1.2.31	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
6.5	CVSS 3.1	Medium	2.8	3.6	security-advisories@github.com via NIST National Vulnerability Database
6.5	CVSS 3.1	Medium	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-22 · Path Traversal

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.49%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Monitor file creation in web directories and paths with traversal sequences (../).

web/proxy/WAF logsnetwork IDS/IPSfile integrity (FIM)endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · cacti/cacti
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 6.5
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 25, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

github.com/Cacti/cacti/security/advisories/GHSA-mjvw-mhj5-9jcj
Exploit, Mitigation, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database
github.com/Cacti/cacti/commit/4c09efaebf3a9faec66969d0b5c4aceaf397f37f
Patch, x_refsource_MISC, NIST National Vulnerability Database

Elsewhere on this site

Cacti
every CVE for this vendor

File handling
same class

CWE-22
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-40941 Cacti: Package Import Signature Validation Bypass Allows Self-Signed Packages Jun 25, 2026
Medium CVE-2026-40080 Cacti: Open Redirect via HTTP_REFERER substring check in auth_login_redirect Jun 25, 2026
Medium CVE-2026-40082 Cacti: Session Fixation via missing session_regenerate_id() after login Jun 25, 2026
High CVE-2026-40083 Cacti: SQL Injection in managers.php Jun 25, 2026
High CVE-2026-39951 Cacti: Stored SQL Injection via graph_name_regexp in Reports feature Jun 24, 2026
Critical CVE-2026-40079 Cacti: OS Command Injection via escape_command() (CVE-2026-40079) Jun 24, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-40084 is "Cacti: Arbitrary File Read via Path Traversal in Report `format_file` Parameter", rated Medium. It affects Cacti (Cacti); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. EPSS 0.49% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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