CVE-2026-82845: Insecure Deserialization (CVSS 9.9)

Description

The Masteriyo LMS WordPress plugin before 3.4.1 does not prevent user-supplied values held as metadata from being deserialized when they are read back, allowing users with a minimal account to inject arbitrary PHP objects and, by way of a class shipped in a library bundled with the Masteriyo LMS WordPress plugin before 3.4.1, write and execute arbitrary code on the server. A weaker form of the same issue is reachable without an account and yields an arbitrary file write rather than code execution.

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CVSS v3.1 Score

9.9

CRITICAL

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

EPSS — Exploit Prediction

0.0035

Probability of exploitation

0.29%

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-502 Deserialization of Untrusted Data

References

Other References

https://wpscan.com/vulnerability/5ced30ea-8b78-495f-b10c-42b3f10adcb3/

Frequently Asked Questions

What is CVE-2026-82845? +

The Masteriyo LMS WordPress plugin before 3.4.1 does not prevent user-supplied values held as metadata from being deserialized when they are read back, allowing users with a minimal account to inject arbitrary PHP objects and, by way of a class shipped in a library bundled with the Masteriyo LMS WordPress plugin before 3.4.1, write and execute arbitrary code on the server. A weaker form of the same issue is reachable without an account and yields an arbitrary file write rather than code execution. It has a CVSS v3.1 base score of 9.9 (CRITICAL).

How severe is CVE-2026-82845? +

CVE-2026-82845 has a CVSS v3.1 score of 9.9 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0035, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-82845? +

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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