GHSA-4M7W-QMGQ-4WJ5

Vulnerability from github – Published: 2026-06-15 20:11 – Updated: 2026-06-15 20:11
VLAI
Summary
aiohttp: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections
Details

Summary

The server_hostname TLS SNI check can be bypassed when an existing connection is reused.

Impact

If an application makes multiple requests to the same domain, but with different per-request server_hostname parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check.

Workaround

Disable keep_alive if you need to change the server_hostname check between requests.

Patch: https://github.com/aio-libs/aiohttp/commit/0ca2b6c28a25726527a8b60f25960262a91ed0e0

Severity
2.7 (Low)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.14.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "aiohttp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.14.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-54275"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-297"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-15T20:11:13Z",
    "nvd_published_at": null,
    "severity": "LOW"
  },
  "details": "### Summary\n\nThe `server_hostname` TLS SNI check can be bypassed when an existing connection is reused.\n\n### Impact\n\nIf an application makes multiple requests to the same domain, but with different per-request `server_hostname` parameters, then the later calls may succeed by reusing the existing connection when they should have been rejected due to the TLS SNI check.\n\n### Workaround\n\nDisable keep_alive if you need to change the `server_hostname` check between requests.\n\n-----\n\nPatch: https://github.com/aio-libs/aiohttp/commit/0ca2b6c28a25726527a8b60f25960262a91ed0e0",
  "id": "GHSA-4m7w-qmgq-4wj5",
  "modified": "2026-06-15T20:11:13Z",
  "published": "2026-06-15T20:11:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-4m7w-qmgq-4wj5"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/aio-libs/aiohttp"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "aiohttp: TLS Server Hostname Override Is Ignored When Reusing HTTPS Connections"
}



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