Vulnerability-Lookup

FKIE_CVE-2026-86863

Vulnerability from fkie_nvd - Published: 2026-09-17 16:18 - Updated: 2026-09-17 17:16

Severity

9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

pgAdmin 4's Webserver authentication source is intended to accept an identity asserted by the web server or reverse proxy in front of pgAdmin, delivered through the WSGI/CGI environment. WebserverAuthentication.get_user() read config.WEBSERVER_REMOTE_USER from request.environ and, when that returned nothing, fell back to reading the same name directly from the inbound HTTP request headers via request.headers.get(). An inbound HTTP header is written by whoever sends the request, so any client able to reach pgAdmin could supply that header itself and be authenticated as any username it named, including an existing Administrator, without presenting a password or any other credential. The environment lookup could also be satisfied by a client-supplied header whenever WEBSERVER_REMOTE_USER was configured to an HTTP_-prefixed or hyphenated name such as HTTP_X_FORWARDED_USER or X-Forwarded-User, since WSGI servers place inbound headers into the environment under exactly those names. Deployments are affected only when 'webserver' is enabled in AUTHENTICATION_SOURCES. The fix distinguishes a genuine CGI/WSGI variable from a header-derived one and implicitly trusts only the former. A header-asserted identity is now accepted only when the operator explicitly opts in via WEBSERVER_REMOTE_USER_FROM_HEADER, the request arrives from a peer listed in WEBSERVER_TRUSTED_PROXIES, and, when configured, a shared secret supplied in WEBSERVER_SHARED_SECRET_HEADER matches WEBSERVER_SHARED_SECRET under a constant-time comparison. The trusted-peer check deliberately reads the real socket peer address rather than request.remote_addr, because ProxyFix rewrites the latter from the client-controlled X-Forwarded-For header and would otherwise allow an attacker to claim to be the trusted proxy. As defence in depth, login() now refuses any account whose auth_source is not 'webserver', so a misconfigured trust gate cannot be used to assume an internal or LDAP account. This issue affects pgAdmin 4: from 6.2 before 9.18.

References

	URL	Tags
	f86ef6dc-4d3a-42ad-8f28-e6d5547a5007	https://github.com/pgadmin-org/pgadmin4/issues/10383

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "modules": [
            "Authentication"
          ],
          "product": "pgAdmin 4",
          "programFiles": [
            "https://github.com/pgadmin-org/pgadmin4/blob/master/web/pgadmin/authenticate/webserver.py"
          ],
          "repo": "https://github.com/pgadmin-org/pgadmin4",
          "vendor": "pgadmin.org",
          "versions": [
            {
              "lessThan": "9.18",
              "status": "affected",
              "version": "6.2",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "pgAdmin 4\u0027s Webserver authentication source is intended to accept an identity asserted by the web server or reverse proxy in front of pgAdmin, delivered through the WSGI/CGI environment. WebserverAuthentication.get_user() read config.WEBSERVER_REMOTE_USER from request.environ and, when that returned nothing, fell back to reading the same name directly from the inbound HTTP request headers via request.headers.get(). An inbound HTTP header is written by whoever sends the request, so any client able to reach pgAdmin could supply that header itself and be authenticated as any username it named, including an existing Administrator, without presenting a password or any other credential. The environment lookup could also be satisfied by a client-supplied header whenever WEBSERVER_REMOTE_USER was configured to an HTTP_-prefixed or hyphenated name such as HTTP_X_FORWARDED_USER or X-Forwarded-User, since WSGI servers place inbound headers into the environment under exactly those names. Deployments are affected only when \u0027webserver\u0027 is enabled in AUTHENTICATION_SOURCES.\n\nThe fix distinguishes a genuine CGI/WSGI variable from a header-derived one and implicitly trusts only the former. A header-asserted identity is now accepted only when the operator explicitly opts in via WEBSERVER_REMOTE_USER_FROM_HEADER, the request arrives from a peer listed in WEBSERVER_TRUSTED_PROXIES, and, when configured, a shared secret supplied in WEBSERVER_SHARED_SECRET_HEADER matches WEBSERVER_SHARED_SECRET under a constant-time comparison. The trusted-peer check deliberately reads the real socket peer address rather than request.remote_addr, because ProxyFix rewrites the latter from the client-controlled X-Forwarded-For header and would otherwise allow an attacker to claim to be the trusted proxy. As defence in depth, login() now refuses any account whose auth_source is not \u0027webserver\u0027, so a misconfigured trust gate cannot be used to assume an internal or LDAP account.\n\nThis issue affects pgAdmin 4: from 6.2 before 9.18."
    }
  ],
  "id": "CVE-2026-86863",
  "lastModified": "2026-09-17T17:16:51.633",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "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:H/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-86863",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-17T16:01:07.262408Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-17T16:18:17.863",
  "references": [
    {
      "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
      "url": "https://github.com/pgadmin-org/pgadmin4/issues/10383"
    }
  ],
  "sourceIdentifier": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-290"
        },
        {
          "lang": "en",
          "value": "CWE-807"
        }
      ],
      "source": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
      "type": "Secondary"
    }
  ]
}

CVE-2026-86863 (GCVE-0-2026-86863)

Vulnerability from cvelistv5 – Published: 2026-09-17 15:30 – Updated: 2026-09-17 16:01

Title

pgAdmin 4: Authentication bypass via a client-controlled identity header in Webserver authentication mode

Summary

Severity

9.8 (Critical)


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

9.3 (Critical)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-17 16:01 UTC

CWE

CWE-290 - Authentication Bypass by Spoofing
CWE-807 - Reliance on Untrusted Inputs in a Security Decision

Assigner

PostgreSQL redhat root

References

1 reference

URL	Tags
https://github.com/pgadmin-org/pgadmin4/issues/10383	issue-tracking

Impacted products

1 product

Vendor	Product	Version
pgadmin.org	pgAdmin 4	Affected: 6.2 , < 9.18 (custom)

Credits

Sanghyeon Lee (@h9e0n, https://github.com/isanghyeon) Kundan Sable <kundan.sable@enterprisedb.com> Hitesh Jambhale <hitesh.jambhale@enterprisedb.com>

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-86863",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-17T16:01:07.262408Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-17T16:01:16.146Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "modules": [
            "Authentication"
          ],
          "product": "pgAdmin 4",
          "programFiles": [
            "https://github.com/pgadmin-org/pgadmin4/blob/master/web/pgadmin/authenticate/webserver.py"
          ],
          "repo": "https://github.com/pgadmin-org/pgadmin4",
          "vendor": "pgadmin.org",
          "versions": [
            {
              "lessThan": "9.18",
              "status": "affected",
              "version": "6.2",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Sanghyeon Lee (@h9e0n, https://github.com/isanghyeon)"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Kundan Sable \u003ckundan.sable@enterprisedb.com\u003e"
        },
        {
          "lang": "en",
          "type": "remediation reviewer",
          "value": "Hitesh Jambhale \u003chitesh.jambhale@enterprisedb.com\u003e"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "pgAdmin 4\u0027s Webserver authentication source is intended to accept an identity asserted by the web server or reverse proxy in front of pgAdmin, delivered through the WSGI/CGI environment. WebserverAuthentication.get_user() read config.WEBSERVER_REMOTE_USER from request.environ and, when that returned nothing, fell back to reading the same name directly from the inbound HTTP request headers via request.headers.get(). An inbound HTTP header is written by whoever sends the request, so any client able to reach pgAdmin could supply that header itself and be authenticated as any username it named, including an existing Administrator, without presenting a password or any other credential. The environment lookup could also be satisfied by a client-supplied header whenever WEBSERVER_REMOTE_USER was configured to an HTTP_-prefixed or hyphenated name such as HTTP_X_FORWARDED_USER or X-Forwarded-User, since WSGI servers place inbound headers into the environment under exactly those names. Deployments are affected only when \u0027webserver\u0027 is enabled in AUTHENTICATION_SOURCES.\n\nThe fix distinguishes a genuine CGI/WSGI variable from a header-derived one and implicitly trusts only the former. A header-asserted identity is now accepted only when the operator explicitly opts in via WEBSERVER_REMOTE_USER_FROM_HEADER, the request arrives from a peer listed in WEBSERVER_TRUSTED_PROXIES, and, when configured, a shared secret supplied in WEBSERVER_SHARED_SECRET_HEADER matches WEBSERVER_SHARED_SECRET under a constant-time comparison. The trusted-peer check deliberately reads the real socket peer address rather than request.remote_addr, because ProxyFix rewrites the latter from the client-controlled X-Forwarded-For header and would otherwise allow an attacker to claim to be the trusted proxy. As defence in depth, login() now refuses any account whose auth_source is not \u0027webserver\u0027, so a misconfigured trust gate cannot be used to assume an internal or LDAP account.\n\nThis issue affects pgAdmin 4: from 6.2 before 9.18."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "Threat model: any unauthenticated client able to reach the pgAdmin login endpoint in a deployment that has \u0027webserver\u0027 enabled in AUTHENTICATION_SOURCES. The attack is a single HTTP request carrying an additional header, so Attack Complexity is Low, Privileges Required is None, and no victim interaction is involved. Confidentiality, Integrity and Availability are all High because the attacker may name an existing Administrator and thereby obtain full control of the pgAdmin installation, including every server definition and stored credential it holds. Scope is Unchanged: although the attacker impersonates another principal, everything compromised is governed by pgAdmin\u0027s own security authority. The configuration precondition (Webserver authentication enabled) is a deployment property rather than an attacker-facing barrier, so it is not modelled as Attack Complexity; the score describes the vulnerable configuration."
            }
          ]
        },
        {
          "cvssV4_0": {
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "Same reasoning as the CVSS 3.1 entry: an unauthenticated attacker asserts an arbitrary identity, including Administrator, with one crafted request and no user interaction. VC:H/VI:H/VA:H because full control of the pgAdmin instance follows directly. SC:N/SI:N/SA:N because the impact is bounded by pgAdmin\u0027s own authority; any onward effect on database servers follows from credentials pgAdmin already held rather than from a distinct subsequent system being compromised by this flaw itself."
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-290",
              "description": "CWE-290 Authentication Bypass by Spoofing",
              "lang": "en",
              "type": "CWE"
            },
            {
              "cweId": "CWE-807",
              "description": "CWE-807 Reliance on Untrusted Inputs in a Security Decision",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-17T15:30:58.077Z",
        "orgId": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
        "shortName": "PostgreSQL"
      },
      "references": [
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/pgadmin-org/pgadmin4/issues/10383"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "pgAdmin 4: Authentication bypass via a client-controlled identity header in Webserver authentication mode"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f86ef6dc-4d3a-42ad-8f28-e6d5547a5007",
    "assignerShortName": "PostgreSQL",
    "cveId": "CVE-2026-86863",
    "datePublished": "2026-09-17T15:30:58.077Z",
    "dateReserved": "2026-09-08T15:47:05.445Z",
    "dateUpdated": "2026-09-17T16:01:16.146Z",
    "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.

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.