CVE-2026-25789

CWE-79Published: May 12, 2026· Updated: May 12, 2026

7.1

CVSS v3.1

EPSS:0.14%probability of exploitation in 30 daysPercentile:33.4th

Official Description

Affected devices do not properly validate and sanitize filenames on the Firmware Update page. This could allow a remote attacker to social engineer the user into selecting the modified firmware file to be uploaded. This would result in malitcious JavaScript execution in the context of the authenticated user's session without requiring the file to be uploaded, potentially leading to session hijacking or credential theft.

NVD Source

Technical Analysis

CVE-2026-25789 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.1.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges Req.Low

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Exploit-DB

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GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

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PacketStorm

Security advisories & exploits

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News & Research Mentioning CVE-2026-25789

Siemens SIMATIC S7 PLC Web Server

CISA Alerts· May 14, 2026

View CSAF Summary SIMATIC S7 PLCs contain multiple vulnerabilities in the web server that could allow an attacker to perform cross-site scripting attacks. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens is preparing further fix versions and recommends specific countermeasures for products where fixes are not, or not yet available. The following versions of Siemens SIMATIC S7 PLC Web Server are affected: SIMATIC Drive Controller CPU 1504D TF (6ES7615-4DF10-0AB0) vers:intdot/<3.1.6 (CVE-2026-25786, CVE-2026-25787, CVE-2026-25789) SIMATIC Drive Controller CPU 1507D TF (6ES7615-7DF10-0AB0) vers:intdot/<3.1.6 (CVE-2026-25786, CVE-2026-25787, CVE-2026-25789) SIMATIC ET 200SP CPU 1510S [xlite_meta score:73 src:CISA Alerts xlite_fp:ef3a512b496625a23af31ebb67fe8fd2aad71c418ba35d35bcb0eefd14a5a88b]