How severe is CVE-2018-21031?

CVE-2018-21031 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2018-21031 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-21031?

CVE-2018-21031 affects Plex Media Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-21031?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-21031 published?

CVE-2018-21031 was published on 2019-11-18 and last updated on 2026-06-17.

CVE-2018-21031

CVE-2018-21031 is a medium-severity vulnerability in Plex Media Server with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-522.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-522
Affected product: Plex Media Server
Published: 2019-11-18
Last modified: 2026-06-17

Description

Tautulli versions 2.1.38 and below allows remote attackers to bypass intended access control in Plex Media Server because the X-Plex-Token is mishandled and can be retrieved from Tautulli. NOTE: Initially, this id was associated with Plex Media Server 1.18.2.2029-36236cc4c as the affected product and version. Further research indicated that Tautulli is the correct affected product.

Frequently asked questions

What is CVE-2018-21031?: Tautulli versions 2.1.38 and below allows remote attackers to bypass intended access control in Plex Media Server because the X-Plex-Token is mishandled and can be retrieved from Tautulli. NOTE: Initially, this id was associated with Plex Media Server 1.18.2.2029-36236cc4c as the affected product and version. Further research indicated that Tautulli is the correct affected product.
How severe is CVE-2018-21031?: CVE-2018-21031 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-21031 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-21031?: CVE-2018-21031 affects Plex Media Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-21031?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-21031 published?: CVE-2018-21031 was published on 2019-11-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:plex:media_server:1.18.2.2029-36236cc4c:*:*:*:*:*:*:*

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