Vulnerability-Lookup

CVE-2026-75922 (GCVE-0-2026-75922)

Vulnerability from cvelistv5 – Published: 2026-08-23 18:16 – Updated: 2026-08-25 19:30

Title

Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line

Summary

Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line. PSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, '?' or '#' truncates it the same way. Everything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy's own routing does not expose.

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-25 19:30 UTC

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests
CWE-93 - Improper Neutralization of CRLF Sequences

Assigner

CPANSec CNA under the redhat root

CNA scorecard C 64/100 over 273 records in the last 180 days details

References

5 references

URL	Tags
https://metacpan.org/release/LNATION/Reverse-Prox…
https://metacpan.org/release/LNATION/Reverse-Prox…
https://metacpan.org/release/LNATION/Reverse-Prox…
https://metacpan.org/release/LNATION/Reverse-Prox…	release-notes
http://www.openwall.com/lists/oss-security/2026/08/23/2

Impacted products

1 product

Vendor	Product	Version	CPE status
		Affected: 0 , < 0.04 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-08-23T21:05:13.636Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/08/23/2"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-75922",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-25T19:30:17.806527Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-25T19:30:38.767Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Reverse::Proxy"
          ],
          "packageName": "Reverse-Proxy",
          "packageURL": "pkg:cpan/Reverse-Proxy",
          "programFiles": [
            "Proxy.xs"
          ],
          "programRoutines": [
            {
              "name": "rp_target_url"
            },
            {
              "name": "rp_raw_request"
            }
          ],
          "versions": [
            {
              "lessThan": "0.04",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line.\n\nPSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, \u0027?\u0027 or \u0027#\u0027 truncates it the same way.\n\nEverything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy\u0027s own routing does not expose."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444 Inconsistent Interpretation of HTTP Requests",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-93",
              "description": "CWE-93 Improper Neutralization of CRLF Sequences",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-23T18:16:41.474Z",
        "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "shortName": "CPANSec"
      },
      "references": [
        {
          "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L386-399"
        },
        {
          "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L654-666"
        },
        {
          "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/source/Proxy.xs#L400-426"
        },
        {
          "tags": [
            "release-notes"
          ],
          "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/changes"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to Reverse-Proxy 0.04 or later."
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line",
      "x_generator": {
        "engine": "cpansec-cna-tool 0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
    "assignerShortName": "CPANSec",
    "cveId": "CVE-2026-75922",
    "datePublished": "2026-08-23T18:16:41.474Z",
    "dateReserved": "2026-08-18T15:10:32.506Z",
    "dateUpdated": "2026-08-25T19:30:38.767Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-75922",
      "date": "2026-10-16",
      "epss": "0.00419",
      "percentile": "0.34738"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://cpan.org/modules",
                "defaultStatus": "unaffected",
                "modules": [
                  "Reverse::Proxy"
                ],
                "packageName": "Reverse-Proxy",
                "packageURL": "pkg:cpan/Reverse-Proxy",
                "programFiles": [
                  "Proxy.xs"
                ],
                "programRoutines": [
                  {
                    "name": "rp_target_url"
                  },
                  {
                    "name": "rp_raw_request"
                  }
                ],
                "versions": [
                  {
                    "lessThan": "0.04",
                    "status": "affected",
                    "version": "0",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line.\n\nPSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, \u0027?\u0027 or \u0027#\u0027 truncates it the same way.\n\nEverything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy\u0027s own routing does not expose."
          },
          {
            "lang": "es",
            "value": "Las versiones de Reverse::Proxy anteriores a la 0.04 para Perl permiten el contrabando de solicitudes HTTP a trav\u00e9s de un PATH_INFO decodificado por porcentaje, escrito sin codificar en la l\u00ednea de solicitud ascendente.\n\nPSGI entrega PATH_INFO a una aplicaci\u00f3n decodificado por porcentaje, por lo que una secuencia %XX en la URL del cliente se ha convertido en un byte sin procesar para cuando el proxy la ve. El proxy a\u00f1ade esa cadena de bytes a la URL base ascendente, y para un t\u00fanel de actualizaci\u00f3n lo escribe en una l\u00ednea de solicitud que serializa \u00e9l mismo, sin recodificar nada en ninguna de las rutas. El cliente HTTP que env\u00eda la URL resultante tampoco valida el objetivo. Una ruta que contiene %0d%0a, por lo tanto, llega al ascendente como un CRLF que termina la l\u00ednea de solicitud, y un espacio decodificado, \u0027?\u0027 o \u0027#\u0027 lo trunca de la misma manera.\n\nTodo lo que el cliente escribe despu\u00e9s del CRLF es le\u00eddo por el ascendente como una segunda solicitud. En la ruta almacenada en b\u00fafer, llega en una conexi\u00f3n keep-alive que el proxy agrupa y reutiliza para otros clientes. Su m\u00e9todo, ruta y encabezados son todos elegidos por el cliente, y el ascendente lo atribuye al proxy, por lo que alcanza rutas ascendentes que el propio enrutamiento del proxy no expone."
          }
        ],
        "id": "CVE-2026-75922",
        "lastModified": "2026-10-14T13:10:00.187",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 5.3,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 1.4,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-75922",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-25T19:30:17.806527Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-08-23T19:16:28.930",
        "references": [
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L386-399"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L654-666"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/changes"
          },
          {
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/source/Proxy.xs#L400-426"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "http://www.openwall.com/lists/oss-security/2026/08/23/2"
          }
        ],
        "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-93"
              },
              {
                "lang": "en",
                "value": "CWE-444"
              }
            ],
            "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2026-08-23T21:05:13.636Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "url": "http://www.openwall.com/lists/oss-security/2026/08/23/2"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "NONE",
                  "baseScore": 5.3,
                  "baseSeverity": "MEDIUM",
                  "confidentialityImpact": "LOW",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-75922",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-08-25T19:30:17.806527Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-08-25T19:30:34.895Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "collectionURL": "https://cpan.org/modules",
              "defaultStatus": "unaffected",
              "modules": [
                "Reverse::Proxy"
              ],
              "packageName": "Reverse-Proxy",
              "packageURL": "pkg:cpan/Reverse-Proxy",
              "programFiles": [
                "Proxy.xs"
              ],
              "programRoutines": [
                {
                  "name": "rp_target_url"
                },
                {
                  "name": "rp_raw_request"
                }
              ],
              "versions": [
                {
                  "lessThan": "0.04",
                  "status": "affected",
                  "version": "0",
                  "versionType": "custom"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line.\n\nPSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, \u0027?\u0027 or \u0027#\u0027 truncates it the same way.\n\nEverything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy\u0027s own routing does not expose."
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-444",
                  "description": "CWE-444 Inconsistent Interpretation of HTTP Requests",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            },
            {
              "descriptions": [
                {
                  "cweId": "CWE-93",
                  "description": "CWE-93 Improper Neutralization of CRLF Sequences",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-08-23T18:16:41.474Z",
            "orgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
            "shortName": "CPANSec"
          },
          "references": [
            {
              "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L386-399"
            },
            {
              "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L654-666"
            },
            {
              "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/source/Proxy.xs#L400-426"
            },
            {
              "tags": [
                "release-notes"
              ],
              "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/changes"
            }
          ],
          "solutions": [
            {
              "lang": "en",
              "value": "Upgrade to Reverse-Proxy 0.04 or later."
            }
          ],
          "source": {
            "discovery": "UNKNOWN"
          },
          "title": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line",
          "x_generator": {
            "engine": "cpansec-cna-tool 0.1"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
        "assignerShortName": "CPANSec",
        "cveId": "CVE-2026-75922",
        "datePublished": "2026-08-23T18:16:41.474Z",
        "dateReserved": "2026-08-18T15:10:32.506Z",
        "dateUpdated": "2026-08-25T19:30:38.767Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-75922

Vulnerability from fkie_nvd - Published: 2026-08-23 19:16 - Updated: 2026-10-14 13:10

Severity

5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Summary

References

	URL	Tags
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L386-399
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L654-666
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/changes
	9b29abf9-4ab0-4765-b253-1875cd9b441e	https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/source/Proxy.xs#L400-426
	af854a3a-2127-422b-91ae-364da2661108	http://www.openwall.com/lists/oss-security/2026/08/23/2

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://cpan.org/modules",
          "defaultStatus": "unaffected",
          "modules": [
            "Reverse::Proxy"
          ],
          "packageName": "Reverse-Proxy",
          "packageURL": "pkg:cpan/Reverse-Proxy",
          "programFiles": [
            "Proxy.xs"
          ],
          "programRoutines": [
            {
              "name": "rp_target_url"
            },
            {
              "name": "rp_raw_request"
            }
          ],
          "versions": [
            {
              "lessThan": "0.04",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line.\n\nPSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, \u0027?\u0027 or \u0027#\u0027 truncates it the same way.\n\nEverything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy\u0027s own routing does not expose."
    },
    {
      "lang": "es",
      "value": "Las versiones de Reverse::Proxy anteriores a la 0.04 para Perl permiten el contrabando de solicitudes HTTP a trav\u00e9s de un PATH_INFO decodificado por porcentaje, escrito sin codificar en la l\u00ednea de solicitud ascendente.\n\nPSGI entrega PATH_INFO a una aplicaci\u00f3n decodificado por porcentaje, por lo que una secuencia %XX en la URL del cliente se ha convertido en un byte sin procesar para cuando el proxy la ve. El proxy a\u00f1ade esa cadena de bytes a la URL base ascendente, y para un t\u00fanel de actualizaci\u00f3n lo escribe en una l\u00ednea de solicitud que serializa \u00e9l mismo, sin recodificar nada en ninguna de las rutas. El cliente HTTP que env\u00eda la URL resultante tampoco valida el objetivo. Una ruta que contiene %0d%0a, por lo tanto, llega al ascendente como un CRLF que termina la l\u00ednea de solicitud, y un espacio decodificado, \u0027?\u0027 o \u0027#\u0027 lo trunca de la misma manera.\n\nTodo lo que el cliente escribe despu\u00e9s del CRLF es le\u00eddo por el ascendente como una segunda solicitud. En la ruta almacenada en b\u00fafer, llega en una conexi\u00f3n keep-alive que el proxy agrupa y reutiliza para otros clientes. Su m\u00e9todo, ruta y encabezados son todos elegidos por el cliente, y el ascendente lo atribuye al proxy, por lo que alcanza rutas ascendentes que el propio enrutamiento del proxy no expone."
    }
  ],
  "id": "CVE-2026-75922",
  "lastModified": "2026-10-14T13:10:00.187",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-75922",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-25T19:30:17.806527Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-23T19:16:28.930",
  "references": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L386-399"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L654-666"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/changes"
    },
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/source/Proxy.xs#L400-426"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "url": "http://www.openwall.com/lists/oss-security/2026/08/23/2"
    }
  ],
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-93"
        },
        {
          "lang": "en",
          "value": "CWE-444"
        }
      ],
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary"
    }
  ]
}

GHSA-5XQ5-HX4G-F5V6

Vulnerability from github – Published: 2026-08-23 21:31 – Updated: 2026-08-25 21:31

Details

Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line.

PSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, '?' or '#' truncates it the same way.

Everything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy's own routing does not expose.

Severity

5.3 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-75922"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-93"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-23T19:16:28Z",
    "severity": "MODERATE"
  },
  "details": "Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line.\n\nPSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the client URL has become a raw byte by the time the proxy sees it. The proxy appends that byte string to the upstream base URL, and for an Upgrade tunnel writes it into a request line it serializes itself, re-encoding nothing in either path. The HTTP client that sends the resulting URL does not validate the target either. A path containing %0d%0a therefore arrives at the upstream as a CRLF that ends the request line, and a decoded space, \u0027?\u0027 or \u0027#\u0027 truncates it the same way.\n\nEverything the client writes after the CRLF is read by the upstream as a second request. On the buffered path it arrives on a keep-alive connection the proxy pools and reuses for other clients. Its method, path and headers are all chosen by the client, and the upstream attributes it to the proxy, so it reaches upstream paths that the proxy\u0027s own routing does not expose.",
  "id": "GHSA-5xq5-hx4g-f5v6",
  "modified": "2026-08-25T21:31:21Z",
  "published": "2026-08-23T21:31:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-75922"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L386-399"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.03/source/Proxy.xs#L654-666"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/changes"
    },
    {
      "type": "WEB",
      "url": "https://metacpan.org/release/LNATION/Reverse-Proxy-0.04/source/Proxy.xs#L400-426"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/08/23/2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

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

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-75922 (GCVE-0-2026-75922)

FKIE_CVE-2026-75922

GHSA-5XQ5-HX4G-F5V6

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour