# CVE-2026-121565: Tanium addressed an improper certificate validation vulnerability in multiple products

Status: published. Published: 2026-11-03. Updated: 2026-11-04.

Tanium addressed an improper certificate validation vulnerability in multiple products. Products have been updated to distrust several intermediate CA certificates associated with compromised private keys.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Tanium / TanOS: ≥ 1.8.5; < 1.8.5.0326 (affected, custom); ≥ 1.8.6; < 1.8.6.0193 (affected, custom); ≥ 1.9.0; < 1.9.0.0089 (affected, custom). Source: CNA: Tanium
- Tanium / Asset: ≥ 1.33; < 1.33.334 (affected, custom); ≥ 1.36; < 1.36.182 (affected, custom); ≥ 1.39; < 1.39.164 (affected, custom). Source: CNA: Tanium
- Tanium / Comply: ≥ 2.32; < 2.32.275 (affected, custom); ≥ 2.35; < 2.35.337 (affected, custom); ≥ 2.37; < 2.37.347 (affected, custom). Source: CNA: Tanium
- Tanium / Connect: ≥ 5.29; < 5.29.272 (affected, custom); ≥ 5.37; < 5.37.177 (affected, custom); ≥ 5.47; < 5.47.135 (affected, custom). Source: CNA: Tanium
- Tanium / Integrity Monitor: ≥ 3.6; < 3.6.608 (affected, custom); ≥ 3.7; < 3.7.383 (affected, custom); ≥ 3.8; < 3.8.362 (affected, custom). Source: CNA: Tanium
- Tanium / Health Check: ≥ 1.13; < 1.13.653 (affected, custom). Source: CNA: Tanium
- Tanium / Endpoint Configuration Toolset Solution: ≥ 1.51; < 1.51.61 (affected, custom); ≥ 1.59; < 1.59.51 (affected, custom); ≥ 1.71; < 1.71.26 (affected, custom). Source: CNA: Tanium
- Tanium / Patch: ≥ 3.24; < 3.24.328 (affected, custom); ≥ 3.28; < 3.28.346 (affected, custom); ≥ 3.32; < 3.32.383 (affected, custom). Source: CNA: Tanium
- Tanium / Performance: ≥ 1.25; < 1.25.196 (affected, custom). Source: CNA: Tanium
- Tanium / Reputation: ≥ 6.6; < 6.6.150 (affected, custom); ≥ 6.7; < 6.7.143 (affected, custom); ≥ 6.8; < 6.8.167 (affected, custom). Source: CNA: Tanium
- Tanium / Reveal: ≥ 2.4; < 2.4.109 (affected, custom); ≥ 2.5; < 2.5.166 (affected, custom). Source: CNA: Tanium
- Tanium / Threat Response: ≥ 4.9; < 4.9.480 (affected, custom); ≥ 4.12; < 4.12.353 (affected, custom); ≥ 4.17; < 4.17.333 (affected, custom). Source: CNA: Tanium
- Tanium / Provision Host: ≥ 10.4.100; < 10.4.100 (affected, semver); ≥ 10.8.115; < 10.8.115 (affected, semver); ≥ 10.9.113; < 10.9.113 (affected, semver); ≥ 10.10.189; < 10.10.189 (affected, semver); ≥ 10.11.127; < 10.11.127 (affected, semver). Source: CNA: Tanium

## Severity and prioritization

- CVSS 3.1: 7.4 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N; source: CNA: Tanium

- CVSS 3.1: 7.4 (high); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N; source: NVD: 3938794e-25f5-4123-a1ba-5cbd7f104512

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-295

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://security.tanium.com/TAN-2026-092 (CNA: Tanium)

- https://security.tanium.com/TAN-2026-092 (3938794e-25f5-4123-a1ba-5cbd7f104512)

## Provenance

- CNA: Tanium: https://www.cve.org/CVERecord?id=CVE-2026-121565; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-121565; retrieved 2026-11-04; source updated 2026-11-03

Revision: dab62da460b6663f115e9afd4a6d95da1613e9eb037335f69c93e0c69f00da42

Canonical: https://y2.dev/cve/CVE-2026-121565

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.