Vulnerability-Lookup

GHSA-P3H9-73G9-X6M3

Vulnerability from github – Published: 2026-06-17 21:34 – Updated: 2026-06-17 21:34

Details

Tinyproxy through 1.11.3, fixed in commit 364cdb6, fails to reject requests containing multiple Content-Length headers with differing values, forwarding all duplicate headers to the backend while using the first value to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.

Severity

9.1 (Critical)


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

9.3 (Critical)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-54388"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-444"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-17T20:17:27Z",
    "severity": "CRITICAL"
  },
  "details": "Tinyproxy through 1.11.3, fixed in commit 364cdb6, fails to reject requests containing multiple Content-Length headers with differing values, forwarding all duplicate headers to the backend while using the first value to determine how many request body bytes to consume. Remote attackers can desynchronize the proxy and backend parser state, allowing injection of arbitrary HTTP requests to the backend to enable cache poisoning, access control bypass, and request hijacking.",
  "id": "GHSA-p3h9-73g9-x6m3",
  "modified": "2026-06-17T21:34:39Z",
  "published": "2026-06-17T21:34:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-54388"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinyproxy/tinyproxy/issues/609"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinyproxy/tinyproxy/pull/610"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinyproxy/tinyproxy/commit/364cdb67e0ea00a8e4a7037e2693e0711e816adb"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-duplicate-content-length-headers"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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-2026-54388 (GCVE-0-2026-54388)

Vulnerability from cvelistv5 – Published: 2026-06-17 19:59 – Updated: 2026-06-18 15:33 X_Open Source

Title

Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers

Summary

Severity

9.3 (Critical)


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

9.1 (Critical)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

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

Assigner

VulnCheck

References

4 references

URL	Tags
https://github.com/tinyproxy/tinyproxy/issues/609	technical-description
https://github.com/tinyproxy/tinyproxy/pull/610	issue-tracking
https://github.com/tinyproxy/tinyproxy/commit/364…	patch
https://www.vulncheck.com/advisories/tinyproxy-ht…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
tinyproxy	tinyproxy	Affected: 0 , ≤ 1.11.3 (semver) Unaffected: 364cdb67e0ea00a8e4a7037e2693e0711e816adb (git)

Date Public

2026-05-07 00:00

Credits

Tristan Madani (@TristanInSec)

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-54388",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-18T15:33:31.245200Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-18T15:33:57.017Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/tinyproxy/tinyproxy/issues/609"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "affected",
          "product": "tinyproxy",
          "repo": "https://github.com/tinyproxy/tinyproxy",
          "vendor": "tinyproxy",
          "versions": [
            {
              "lessThanOrEqual": "1.11.3",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "364cdb67e0ea00a8e4a7037e2693e0711e816adb",
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          "type": "finder",
          "value": "Tristan Madani (@TristanInSec)"
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      "datePublic": "2026-05-07T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
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        }
      ],
      "metrics": [
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            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
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          "scenarios": [
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              "type": "CWE"
            }
          ]
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      ],
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          "name": "Researcher Pull Request",
          "tags": [
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        },
        {
          "name": "Maintainer Pull Request",
          "tags": [
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          "url": "https://github.com/tinyproxy/tinyproxy/pull/610"
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        {
          "name": "Patch Commit",
          "tags": [
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        },
        {
          "tags": [
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          ],
          "url": "https://www.vulncheck.com/advisories/tinyproxy-http-request-smuggling-via-duplicate-content-length-headers"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "tags": [
        "x_open-source"
      ],
      "title": "Tinyproxy - HTTP Request Smuggling via Duplicate Content-Length Headers",
      "x_generator": {
        "engine": "vulncheck"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-54388",
    "datePublished": "2026-06-17T19:59:00.000Z",
    "dateReserved": "2026-06-12T20:20:02.950Z",
    "dateUpdated": "2026-06-18T15:33:57.017Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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

GHSA-P3H9-73G9-X6M3

CVE-2026-54388 (GCVE-0-2026-54388)

Tags

Sightings

Nomenclature