Cyber Resilience

CVE-2020-5741

RCE in Plex Media Server ≤ 1.19.3

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRCEDeserialization
Published
08 May 2020
Modified
31 October 2025
KEV Added
10 March 2023
CVSS Score v3.1 7.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.73 99.4th percentile
Risk Priority 79 floored blend · peak EPSS

Summary

CVE-2020-5741 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Plex Media Server. Its CVSS base score is 7.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 0.6% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2020-5741 is a deserialization of untrusted data vulnerability, tracked under CWE-502, that affects Plex Media Server running on Windows. The flaw permits remote code execution through unsafe handling of serialized Python objects, as reflected in its CVSS 3.1 score of 7.2 with network attack vector, low complexity, and high impact on confidentiality, integrity, and availability.

A remote attacker who already possesses valid authenticated credentials can supply a malicious serialized object to the server, resulting in arbitrary Python code execution on the Windows host. The attack requires no user interaction and can fully compromise the affected system.

The vulnerability appears in CISA's catalog of known exploited vulnerabilities and has public exploit code referenced in Tenable research advisory TRA-2020-32 along with Packet Storm disclosures, confirming active interest from attackers. No specific patch or configuration guidance is detailed in the provided references.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Deserialization of Untrusted Data in Plex Media Server on Windows allows a remote, authenticated attacker to execute arbitrary Python code.

CWE(s)
KEV Date Added
10 March 2023

Related Threats

MITRE ATT&CK Enterprise Techniques

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.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2022-47986Same product: Microsoft Windowsboth on KEV
CVE-2026-20963Same vendor: Microsoftboth on KEV
CVE-2020-17144Same vendor: Microsoftboth on KEV
CVE-2026-45659Same vendor: Microsoftboth on KEV
CVE-2020-0618Same vendor: Microsoftboth on KEV
CVE-2024-38094Same vendor: Microsoftboth on KEV
CVE-2021-26857Same vendor: Microsoftboth on KEV
CVE-2026-58644Same vendor: Microsoftboth on KEV
CVE-2025-59287Same vendor: Microsoftboth on KEV
CVE-2025-53770Same vendor: Microsoftboth on KEV

Affected Assets

plex
media server
≤ 1.19.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-502

Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.

addresses: CWE-502

Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.

addresses: CWE-502

Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.

addresses: CWE-502

Validates or rejects untrusted serialized data before deserialization occurs.

addresses: CWE-502

Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.

addresses: CWE-502

Integrity verification of serialized information can detect tampering before deserialization occurs.

addresses: CWE-502

Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 none match
prevents

PR.PS-02 addresses only post-deployment updates/patching and cannot prevent introduction of unsafe deserialization code, yet it can remediate some instances when the flaw exists in outdated libraries or components.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing includes validation of deserialization routines and the use of untrusted data, reducing the likelihood that unsafe object reconstruction will be deployed.

prevents

Requiring vetted libraries, regular updates and SAST before release reduces the likelihood that deserialization logic will accept and act on attacker-controlled serialized objects.

finds

Regular scanning of third-party libraries and timely patching reduce the likelihood that unsafe deserialization vulnerabilities remain active.

none

Mandatory malware scanning of data received over networks or storage media intercepts malicious serialized payloads before they are deserialized by the target application.

References