Vulnerability-Lookup

GHSA-VV2W-R86M-5W27

Vulnerability from github – Published: 2026-10-15 09:30 – Updated: 2026-10-15 09:30

Details

When Jetty's HttpClient make a request to a server through a forward proxy, the server may reply with a 407 (Proxy Authentication Required).

The client mistakenly interprets the 407 as coming from the proxy, so it re-sends the request with the Proxy-Authentication header, which arrives to the server, that now has access to the proxy credentials.

Severity

8.2 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-77711"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-200"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-15T09:17:18Z",
    "severity": "HIGH"
  },
  "details": "When Jetty\u0027s `HttpClient` make a request to a server through a forward proxy, the server may reply with a 407 (Proxy Authentication Required).\n\n\n\nThe client mistakenly interprets the 407 as coming from the proxy, so it re-sends the request with the `Proxy-Authentication` header, which arrives to the server, that now has access to the proxy credentials.",
  "id": "GHSA-vv2w-r86m-5w27",
  "modified": "2026-10-15T09:30:36Z",
  "published": "2026-10-15T09:30:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/jetty/jetty.project/security/advisories/GHSA-r2c5-3p8g-wpvw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-77711"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.eclipse.org/security/cve-assignment/-/work_items/238"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-77711 (GCVE-0-2026-77711)

Vulnerability from cvelistv5 – Published: 2026-10-15 08:51 – Updated: 2026-10-15 13:50

Summary

When Jetty's `HttpClient` make a request to a server through a forward proxy, the server may reply with a 407 (Proxy Authentication Required). The client mistakenly interprets the 407 as coming from the proxy, so it re-sends the request with the `Proxy-Authentication` header, which arrives to the server, that now has access to the proxy credentials.

Severity

8.2 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-15 13:50 UTC

CWE

CWE-200

Assigner

eclipse CNA under the mitre root

CNA scorecard C 63/100 over 146 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/jetty/jetty.project/security/a…
https://gitlab.eclipse.org/security/cve-assignmen…

Impacted products

1 product

Vendor	Product	Version
Eclipse Foundation	Eclipse Jetty	Affected: 12.1.0 , ≤ 12.1.12 (semver) Affected: 12.0.0 , ≤ 12.0.38 (semver) Affected: 11.0.0 , ≤ 11.0.32 (semver) Affected: 10.0.0 , ≤ 10.0.32 (semver) Affected: 9.4.0 , ≤ 9.4.64 (semver)

Credits

https://github.com/4ra1n https://github.com/pyn3rd https://github.com/unam4

Show details on NVD website

JSON

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                  },
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                    "Technical Impact": "partial"
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                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-15T13:50:25.620133Z",
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            "url": "https://github.com/jetty/jetty.project/security/advisories/GHSA-r2c5-3p8g-wpvw"
          }
        ],
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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.

Vulnerability timeline

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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