Cyber Resilience

CVE-2026-27991

High

Published: 05 March 2026

Published
05 March 2026
Modified
22 April 2026
KEV Added
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Patch
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CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0040 32.0th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-27991 is a high-severity PHP Remote File Inclusion (CWE-98) vulnerability. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 32.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2026-27991 is an Improper Control of Filename for Include/Require Statement in PHP Program vulnerability, classified as PHP Remote File Inclusion but enabling PHP Local File Inclusion, in the ThemeREX Avventure WordPress theme. This issue affects Avventure versions from n/a through 1.1.12.

Unauthenticated remote attackers (AV:N/PR:N) can exploit the vulnerability over the network, though it requires high attack complexity (AC:H) and no user interaction (UI:N). Successful exploitation results in high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H) with no scope change (S:U), yielding a CVSS v3.1 base score of 8.1. The weakness is mapped to CWE-98.

The Patchstack advisory documents this Local File Inclusion vulnerability specifically in WordPress Avventure theme version 1.1.12.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in ThemeREX Avventure avventure allows PHP Local File Inclusion.This issue affects Avventure: from n/a through <= 1.1.12.

CWE(s)
CWE-98

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
Why these techniques?

CVE-2026-27991 is an LFI vulnerability in a public-facing WordPress theme exploitable remotely (T1190), enabling attackers to include and execute arbitrary local files, facilitating data extraction from the local system (T1005).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-60057Shared CWE-98
CVE-2025-58940Shared CWE-98
CVE-2026-22476Shared CWE-98
CVE-2025-67980Shared CWE-98
CVE-2025-69034Shared CWE-98
CVE-2025-58225Shared CWE-98
CVE-2026-22427Shared CWE-98
CVE-2025-69402Shared CWE-98
CVE-2025-64205Shared CWE-98
CVE-2026-28013Shared CWE-98

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Requires timely remediation of the specific PHP file inclusion flaw in the Avventure WordPress theme to prevent exploitation.

SI-10 Information Input Validation good match
prevent

Directly addresses improper filename control by mandating validation of inputs to PHP include/require statements, blocking arbitrary local file inclusion.

CM-6 Configuration Settings partial match
prevent

Enforces secure PHP configuration settings like open_basedir to restrict file system access, mitigating LFI even if input validation is bypassed.

References