# CVE-2026-19552: ssl.get_server_certificate(addr, ca_certs=...) verifies the chain but never the identity

Status: published. Published: 2026-11-09. Updated: 2026-11-10.

When ca_certs parameter was supplied to ssl.get_server_certificate() function, the identity of the certificate is not checked.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: PSF) — https://github.com/python/cpython/pull/161507
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: PSF) — https://github.com/python/cpython/commit/8dde46eaa6baf5f027a7234845b20d50b509624e

## Affected products and versions

- Python Software Foundation / CPython: ≥ 0; < 3.16.0 (affected, python). Source: CNA: PSF

## Severity and prioritization

- CVSS 4.0: 0 (none); 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; source: CNA: PSF

- CVSS 4.0: 0 (none); 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/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@python.org

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: Not reported

## Exploit evidence

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

## References

- https://github.com/python/cpython/pull/161507 (CNA: PSF; patch)

- https://github.com/python/cpython/issues/161503 (CNA: PSF; issue-tracking)

- https://mail.python.org/archives/list/security-announce@python.org/thread/SXBD6BGHDBTGM4KSUMQEWYIQ5RO4BQ76/ (CNA: PSF; vendor-advisory)

- https://github.com/python/cpython/commit/8dde46eaa6baf5f027a7234845b20d50b509624e (CNA: PSF; patch)

- http://www.openwall.com/lists/oss-security/2026/11/09/25 (ADP: CVE)

- https://github.com/python/cpython/issues/161503 (cna@python.org)

- https://github.com/python/cpython/pull/161507 (cna@python.org)

- https://mail.python.org/archives/list/security-announce@python.org/thread/SXBD6BGHDBTGM4KSUMQEWYIQ5RO4BQ76/ (cna@python.org)

- http://www.openwall.com/lists/oss-security/2026/11/09/25 (af854a3a-2127-422b-91ae-364da2661108)

## Provenance

- CNA: PSF: https://www.cve.org/CVERecord?id=CVE-2026-19552; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19552; retrieved 2026-11-10; source updated 2026-11-09

Revision: 5f220df99ef43f178e0b3967c0711d111f657f2b8656e5c93ecca800984be5c7

Canonical: https://y2.dev/cve/CVE-2026-19552

## 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.