Description
When ca_certs parameter was supplied to ssl.get_server_certificate() function, the identity of the certificate is not checked.
Published: 2026-11-09
Score: 0 Low
EPSS: n/a
KEV: No
Impact: Man‑in‑the‑Middle / Unauthorized Access
Action: Assess Impact
AI Analysis

Impact

The flaw allows an attacker to intercept TLS connections that use Python's ssl.get_server_certificate with the ca_certs argument, because the function verifies the certificate chain but does not verify that the certificate belongs to the intended host. This omission permits a man‑in‑the‑middle attack in which a malicious server presents a trusted certificate chain to the client while the identity of the host is never verified, potentially exposing sensitive data and enabling credential theft.

Affected Systems

Affected systems are CPython implementations distributed by the Python Software Foundation. No specific version range is provided, so any release that contains the unpatched ssl module may be vulnerable. Administrators should review the Python changelog for a fix once available.

Risk and Exploitability

The EPSS score is not available and the vulnerability is not listed in CISA KEV, but the lack of hostname verification makes it a serious risk. The likely exploitation path involves passive network interception or DNS spoofing; however, this inference is based on the nature of the vulnerability rather than explicit statement in the data. The CVSS metric is missing, and the potential impact on confidentiality, integrity, and availability warrants immediate attention.

Generated by OpenCVE AI on November 9, 2026 at 16:21 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade to a patched Python release that enforces server identity in ssl.get_server_certificate when ca_certs is provided.
  • If an upgraded Python is not available, avoid using ca_certs with ssl.get_server_certificate; instead perform explicit hostname verification or use a library that does it.
  • Ensure all remote TLS connections have hostname verification enabled and test connectivity against trusted certificates.

Generated by OpenCVE AI on November 9, 2026 at 16:21 UTC.

Tracking

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Advisories

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History

Mon, 09 Nov 2026 16:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-297

Mon, 09 Nov 2026 14:30:00 +0000

Type Values Removed Values Added
Description When ca_certs parameter was supplied to ssl.get_server_certificate() function, the identity of the certificate is not checked.
Title ssl.get_server_certificate(addr, ca_certs=...) verifies the chain but never the identity
References
Metrics cvssV4_0

{'score': 0, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N'}


Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: PSF

Published:

Updated: 2026-11-09T14:15:31.799Z

Reserved: 2026-08-11T15:22:01.993Z

Link: CVE-2026-19552

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-09T15:17:21.017

Modified: 2026-11-09T15:17:21.123

Link: CVE-2026-19552

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-09T16:30:12Z

Weaknesses
  • CWE-297

    Improper Validation of Certificate with Host Mismatch