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CVE-2026-9156 Tanium CVE debrief

Tanium addressed a denial of service vulnerability in Tanium Server. The vulnerability was published on 2026-05-27 with a CVSS 3.1 score of 6.5 (MEDIUM severity). The NVD entry indicates a CVSS vector of CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, though this vector appears inconsistent with the described denial of service impact—analysts should verify the official Tanium advisory for authoritative scoring details. The weakness is classified as CWE-772 (Missing Release of Resource after Effective Lifetime). No known exploitation in ransomware campaigns has been documented, and the vulnerability is not listed in CISA KEV. Organizations using Tanium Server should consult the vendor security advisory for patch availability and deployment guidance.

Vendor
Tanium
Product
Tanium Server
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-27
Original CVE updated
2026-07-23
Advisory published
2026-05-27
Advisory updated
2026-07-23

Who should care

Organizations running Tanium Server for endpoint management and security operations; security teams responsible for vulnerability management in enterprise endpoint protection platforms.

Technical summary

CVE-2026-9156 is a denial of service vulnerability in Tanium Server. The underlying weakness relates to missing release of resource after effective lifetime (CWE-772), which can lead to resource exhaustion. The vulnerability requires low attack complexity and low privileges, with network attack vector. Organizations should prioritize obtaining and applying patches from Tanium per their security advisory TAN-2026-013.

Defensive priority

medium

Recommended defensive actions

  • Review Tanium security advisory TAN-2026-013 for official patch information and deployment instructions
  • Verify actual CVSS scoring with vendor documentation due to vector/description inconsistency
  • Assess Tanium Server deployment exposure to network-accessible attack vectors
  • Monitor Tanium security channels for updated guidance or revised scoring
  • Apply vendor-recommended patches according to organizational change management procedures

Evidence notes

CVE description states denial of service; CVSS vector from NVD source metadata shows C:H/I:N/A:N which suggests confidentiality impact rather than availability—this discrepancy warrants verification against the primary vendor source.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-9156 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-9156

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-9156 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-9156

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://security.tanium.com/TAN-2026-013

    3938794e-25f5-4123-a1ba-5cbd7f104512

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.