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ExploitedIn CISA KEVFix available

CVE-2026-96656

Exploitation confirmed. First attested on 2026-10-19 by CISA-ADP, CISA KEV, GCVE · previdian.

  • Published2026-09-23
  • Fixed in1.43.3.10861
  • WeaknessCWE-73

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2026-09-2317:17CVE publishedNVD
  2. 2026-10-1911:50Listed as exploited by GCVEGCVE
  3. 2026-10-1911:50Exploitation first reportedGCVE
  4. 2026-10-20Added to the CISA KEV catalogCISA KEV
  5. 2026-10-2019:46SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-11-13 21:37 UTC
Indicators tagged with this CVE, per day6 indicators over 7 days
13
IndicatorSeen
ota.proxystream.st22 h ago
autoccb.tech22 h ago
217.60.194.11622 h ago
www.autoccb.tech22 h ago
77.90.185.20523 h ago
202.78.167.5523 h ago
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-96656?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-96656?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Plex media server
BranchAffectedFixed in
1.43< 1.43.3.108611.43.3.10861

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA1 product

As cisa-cg, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • Plex Media Serverother versions: unknown
    Affected
    • < 1.43.3.10861fixed in 1.43.3.10861custom

    Not affected = 1.43.3.10861

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-09-23

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • VA-26-266-01 CISA1 product fixed · 1 known affected

    Plex Media Server

    Plex Media Server <1.43.3.10861

Full record on NVD

Fix

  1. Update Plex media server to 1.43.3.10861
  2. CISA’s 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.due 2026-10-23
  3. Vendor fix CISA VA-26-266-01 · 1 productFixed in 1.43.3.10861.

Advisories and patches

Detection

read 2026-11-01 01:02 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

CISA Known Exploited Vulnerability

Date Added
2026-10-20
Patch Due Date
2026-10-23
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.

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0 vector
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
Published
2026-09-23
Last Modified
2026-10-21
NVD status
Analyzed
GitHub Advisory
GHSA-2g2v-9wf5-6m3g

Frequently asked questions

What is CVE-2026-96656?

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.

Is CVE-2026-96656 actively exploited?

Yes. CVE-2026-96656 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2026-10-23.

What is the CVSS score for CVE-2026-96656?

CVE-2026-96656 has a CVSS v3 base score of 7.2 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

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Same product first, then the same vendor advisory and the same publication week.

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Sources for this record