CVE-2026-25789

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.

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CVSS v3.1 Score

7.1

HIGH

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

EPSS — Exploit Prediction

0.0014

Probability of exploitation

0.34%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://cert-portal.siemens.com/productcert/html/ssa-688146.html

Frequently Asked Questions

What is CVE-2026-25789? +

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. It has a CVSS v3.1 base score of 7.1 (HIGH).

How severe is CVE-2026-25789? +

CVE-2026-25789 has a CVSS v3.1 score of 7.1 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0014, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-25789? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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