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CVE-2026-96656

High8.6CISA KEV — exploited in the wild

Plex Media Server before 1.43.3.10861 allows an admin user to write arbitrary files that may be executed on load. The preference TranscoderH264Options is appended verbatim to x264's option string on every transcode. At startup, all .so files are run without signature, execute bit, or symbol checks.

CVSS
8.6v4.0
EPSS (exploit probability)
0.4%32th pct
CISA KEV
Listed

EPSS trendFIRST daily scores, last 90 days

FIRST EPSS held steady from 0.3% on 2026-09-24 to 0.4% on 2026-10-20, ranging 0.3%–0.4% across 25 daily scores.
2026-09-24 → 2026-10-20 · 25 days · 0.3%–0.4%
Daily values
FIRST EPSS daily scores for this CVE
Score dateEPSSPercentile
2026-10-200.4%32.3%
2026-10-190.4%32.3%
2026-10-180.4%32.2%
2026-10-160.4%32.2%
2026-10-150.4%32.1%
2026-10-140.4%32.1%
2026-10-130.4%31.9%
2026-10-120.4%31.8%
2026-10-110.4%31.8%
2026-10-100.4%31.8%
2026-10-090.4%31.7%
2026-10-080.4%31.7%
2026-10-070.4%31.6%
2026-10-060.4%31.6%
2026-10-050.4%31.5%
2026-10-040.4%31.4%
2026-10-030.4%31.5%
2026-10-020.4%31.4%
2026-10-010.4%31.4%
2026-09-300.4%31.3%
2026-09-290.3%24.8%
2026-09-270.3%24.8%
2026-09-260.3%24.8%
2026-09-250.3%24.6%
2026-09-240.3%24.6%

CISA KEV entrycatalogue 2026.10.20

Date added
2026-10-20
Federal due date
2026-10-23
Known ransomware use
Unknown

Required action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Verbatim from the CISA KEV catalogue (CISA KEV, fetched 2026-10-21 07:34 UTC). The due date applies to US federal agencies under BOD 22-01.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • plex media server

Coverage1 article

References

Facts sourced from NVD, FIRST EPSS, and CISA KEV. Last synced 2026-10-21 07:34 UTC.

  • CVSS & description: NVD 2.0, fetched 2026-10-21 06:34 UTC
  • EPSS: FIRST EPSS, fetched 2026-10-21 07:34 UTC; score date 2026-10-20
  • KEV: CISA KEV, fetched 2026-10-21 07:34 UTC