Vulnerability-Lookup

MSRC_CVE-2026-58055

Vulnerability from csaf_microsoft - Published: 2026-06-02 00:00 - Updated: 2026-06-29 01:06

Summary

nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length

Notes

Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

CVE-2026-58055

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Affected products

Under investigation 1 product

Product	Identifier	Version	Remediation
Unresolved product id: 17084-1		—

References

4 references

URL	Category
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self
https://support.microsoft.com/lifecycle	external
https://www.first.org/cvss	external
https://msrc.microsoft.com/csaf/vex/2026/msrc_cve…	self

JSON

To clipboard

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
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    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
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        "category": "self",
        "summary": "CVE-2026-58055 nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-58055.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length",
    "tracking": {
      "current_release_date": "2026-06-29T01:06:34.000Z",
      "generator": {
        "date": "2026-06-29T07:10:52.189Z",
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          "date": "2026-06-29T01:06:34.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-58055",
      "cwe": {
        "id": "CWE-444",
        "name": "Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)"
      },
      "notes": [
        {
          "category": "general",
          "text": "VulnCheck",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "under_investigation": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-58055 nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-58055.json"
        }
      ],
      "title": "nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length"
    }
  ]
}

CVE-2026-58055 (GCVE-0-2026-58055)

Vulnerability from cvelistv5 – Published: 2026-06-28 01:32 – Updated: 2026-06-29 13:51

Title

nghttp2 nghttpx - HTTP Request/Response Smuggling via Upgrade Request with Content-Length

Summary

nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.

Severity

5.4 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

6.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:L/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

VulnCheck

References

3 references

URL	Tags
https://github.com/bikini/exploitarium/tree/main/…	exploitthird-party-advisory
https://github.com/nghttp2/nghttp2/commit/ab28105…	patch
https://www.vulncheck.com/advisories/nghttp2-nght…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
nghttp2	nghttp2	Affected: 0 , ≤ 1.69.0 (semver)

Date Public

2026-06-26 00:00

Credits

ashdfrkl

Show details on NVD website

JSON

To clipboard

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                  },
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                  },
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                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-29T13:51:50.981193Z",
                "version": "2.0.3"
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              "type": "ssvc"
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

MSRC_CVE-2026-58055

CVE-2026-58055 (GCVE-0-2026-58055)

Tags

Sightings

Nomenclature