Vulnerability-Lookup

GHSA-W9JQ-4XJW-37GJ

Vulnerability from github – Published: 2026-08-29 18:31 – Updated: 2026-08-29 18:31

Details

pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification.

Severity

6.5 (Medium)


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

6.9 (Medium)


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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-82462"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-345"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-29T17:17:58Z",
    "severity": "MODERATE"
  },
  "details": "pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification.",
  "id": "GHSA-w9jq-4xjw-37gj",
  "modified": "2026-08-29T18:31:31Z",
  "published": "2026-08-29T18:31:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82462"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237e"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pac4j/pac4j"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-oidc/src/main/java/org/pac4j/oidc/credentials/extractor/OidcCredentialsExtractor.java"
    },
    {
      "type": "WEB",
      "url": "https://www.pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.html"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/pac4j-oidc-before-6.5.6-authentication-bypass-via-access-token-substitution"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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-2026-82462 (GCVE-0-2026-82462)

Vulnerability from cvelistv5 – Published: 2026-08-29 16:35 – Updated: 2026-08-29 16:35

Title

pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution

Summary

Severity

6.9 (Medium)


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

6.5 (Medium)


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

CWE

CWE-345 - Insufficient Verification of Data Authenticity

Assigner

VulnCheck mitre root

References

5 references

URL	Tags
https://github.com/pac4j/pac4j/commit/2270c3ff70e…	patch
https://www.pac4j.org/blog/security-advisory-pac4…	vendor-advisory
https://github.com/pac4j/pac4j/blob/pac4j-parent-…	technical-description
https://github.com/pac4j/pac4j	product
https://www.vulncheck.com/advisories/pac4j-oidc-b…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
pac4j	pac4j	Affected: 0 , < 6.5.6 (semver) cpe:2.3:a:pac4j:pac4j::::::::

Date Public

2026-08-24 00:00

Credits

Joshua Rogers (AISLE Research)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:maven/org.pac4j/pac4j-parent",
          "product": "pac4j",
          "vendor": "pac4j",
          "versions": [
            {
              "lessThan": "6.5.6",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:pac4j:pac4j:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.5.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Joshua Rogers (AISLE Research)"
        }
      ],
      "datePublic": "2026-08-24T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-345",
              "description": "Insufficient Verification of Data Authenticity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-29T16:35:26.177Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "Patch Commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/pac4j/pac4j/commit/2270c3ff70e93cc43831e75702acd5135531237e"
        },
        {
          "name": "pac4j Security Advisory for pac4j-core, pac4j-oidc and pac4j-saml",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.pac4j.org/blog/security-advisory-pac4j-core-oidc-saml.html"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-oidc/src/main/java/org/pac4j/oidc/credentials/extractor/OidcCredentialsExtractor.java"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/pac4j/pac4j"
        },
        {
          "name": "VulnCheck Advisory: pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/pac4j-oidc-before-6.5.6-authentication-bypass-via-access-token-substitution"
        }
      ],
      "title": "pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-82462",
    "datePublished": "2026-08-29T16:35:26.177Z",
    "dateReserved": "2026-08-29T14:11:00.606Z",
    "dateUpdated": "2026-08-29T16:35:26.177Z",
    "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.

Action not permitted

GHSA-W9JQ-4XJW-37GJ

CVE-2026-82462 (GCVE-0-2026-82462)

Tags

Sightings

Nomenclature