# CVE-2026-120808: Certificate Validation Bypass via IPv6 trust-result skip in macOS TLS client

Status: published. Published: 2026-11-10. Updated: 2026-11-13.

An issue exists in MongoDB's macOS TLS client implementation where certificate chain-of-trust validation is bypassed for outbound connections to IPv6-addressed peers. When a MongoDB process using the Apple SecureTransport TLS backend connects to an IPv6 target, the trust evaluation result from SecTrustEvaluate is silently discarded, regardless of whether the peer's certificate is trusted. An on-path party could exploit this by presenting a self-signed certificate containing the target's IPv6 address in the Subject Alternative Name to intercept and modify encrypted inter-node or external service traffic. This issue only affects MongoDB processes running on macOS with the Apple SecureTransport TLS provider.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- MongoDB / MongoDB Server: ≥ 9.0.0; < 9.0.7 (affected, semver); ≥ 8.3.0; < 8.3.16 (affected, semver); ≥ 8.0.0; < 8.0.37 (affected, semver); ≥ 7.0.0; < 7.0.48 (affected, semver). Source: CNA: mongodb

## Severity and prioritization

- CVSS 4.0: 9.1 (critical); CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: mongodb

- 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: mongodb

- CVSS 4.0: 9.1 (critical); CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/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; source: NVD: cna@mongodb.com

- 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: cna@mongodb.com

- CISA KEV: No listing in collected sources

- EPSS: 0.17% as of 2026-11-13; percentile 6.82%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-295

## Exploit evidence

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

## References

- https://jira.mongodb.org/browse/SERVER-130681 (CNA: mongodb)

- https://jira.mongodb.org/browse/SERVER-130681 (cna@mongodb.com)

## Provenance

- CNA: mongodb: https://www.cve.org/CVERecord?id=CVE-2026-120808; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-120808; retrieved 2026-11-11; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-120808; retrieved 2026-11-13; source updated Not reported

Revision: 758c8c2398e9b74bfbde9ca21416ad35ae2bef480e7dd3556796793150fbc3d3

Canonical: https://y2.dev/cve/CVE-2026-120808

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