CVE-2026-27891 | Remote Code Execution (RCE) via Zip Slip in Plugin Upload Mechanism

FacturaScripts is an open source accounting and invoicing software. Versions 2026 and below contain a critical vulnerability in the Plugins::add() function. The system fails to properly validate the file paths within uploaded ZIP archives. This allows an attacker to perform a Zip Slip attack, leading to Arbitrary File Write and Remote Code Execution (RCE) by overwriting sensitive .php files outside the designated plugins directory. The vulnerability is located in Plugins.php. While the testZipFile function attempts to validate that the ZIP contains only one root folder, it does not sanitize or validate the individual file paths within that folder. An attacker can bypass this check by naming a file ValidPluginName/../../shell.php. The explode function will see ValidPluginName as the root folder, satisfying the count($folders) != 1 check. However, during extraction, the ../../ sequence triggers a path traversal, allowing the file to be written anywhere the web server has permissions the root directory. This issue is fixed in version 2026.1.

Published: 2026-05-18 Last update: 2026-05-19 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-27891 is rated Moderate Risk (43.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.52%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-27891

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.16% 0.52% +0.36%
2 2026-05-24 0.11% 0.16% +0.05%
3 2026-05-19 — 0.11% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-27891

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 5.9 [email protected]

Weakness enumeration for CVE-2026-27891

GitHub Security Advisory for CVE-2026-27891

GHSA-3pgc-xqg9-cfr6 · Severity: high · Ecosystem: composer — FacturaScripts Vulnerable to Remote Code Execution (RCE) via Zip Slip in Plugin Upload Mechanism

Affected software / configurations for CVE-2026-27891

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-27891

cvelogic Threat Intelligence