FKIE_CVE-2026-88952

Vulnerability from fkie_nvd - Published: 2026-09-17 15:16 - Updated: 2026-09-18 18:16
Severity
9.1 (Critical) - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Summary
Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker to be signed in as another user by linking an OAuth2 identity to an account that is not theirs. AshAuthentication.Strategy.OAuth2.UserResolver.resolve/3 matches an existing account using the register action's upsert_identity keys, then gates linking the incoming provider identity to it on email_trusted?/2, which reads only the provider's email_verified boolean and never compares the provider's email value with the matched account's email. That gate assumes the account was matched by its email field, so under any other upsert_identity it is vacuous and an attacker presenting their own verified email is attached to, and issued a session for, an account matched on some other attribute. The same unguarded gate applies in OAuth2.SignInPreparation on the registration_enabled? false path, where the account is matched by the sign-in action's read filter instead. The upsert also rewrites the matched account's email to the attacker's address, so later account recovery reaches the attacker rather than the owner. This issue affects ash_authentication: from 4.14.0 before 4.15.0 and from 5.0.0-rc.10 before 5.0.0-rc.14.
References
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://cna.erlef.org/cves/CVE-2026-88952.html
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/commit/2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/commit/42edcd8ebb13fafbb168f12591d7518ce0611fec
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/commit/64530644f9b37ebb76ca14aeb83a77597a0034b7
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/commit/738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/security/advisories/GHSA-wc6x-276q-jrf9
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://osv.dev/vulnerability/EEF-CVE-2026-88952
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027",
            "\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027",
            "\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027",
            "\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027"
          ],
          "packageName": "ash_authentication",
          "packageURL": "pkg:hex/ash_authentication",
          "product": "ash_authentication",
          "programFiles": [
            "lib/ash_authentication/strategies/oauth2/user_resolver.ex",
            "lib/ash_authentication/strategies/oauth2/sign_in_preparation.ex",
            "lib/ash_authentication/strategies/oauth2/identity_change.ex",
            "lib/ash_authentication/strategies/dynamic_oidc/identity_change.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:resolve/3"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:email_trusted?/2"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027:prepare/3"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027:change/3"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027:change/3"
            }
          ],
          "repo": "https://github.com/team-alembic/ash_authentication",
          "vendor": "team-alembic",
          "versions": [
            {
              "lessThan": "4.15.0",
              "status": "affected",
              "version": "4.14.0",
              "versionType": "semver"
            },
            {
              "lessThan": "5.0.0-rc.14",
              "status": "affected",
              "version": "5.0.0-rc.10",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027",
            "\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027",
            "\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027",
            "\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027"
          ],
          "packageName": "team-alembic/ash_authentication",
          "packageURL": "pkg:github/team-alembic/ash_authentication",
          "product": "ash_authentication",
          "programFiles": [
            "lib/ash_authentication/strategies/oauth2/user_resolver.ex",
            "lib/ash_authentication/strategies/oauth2/sign_in_preparation.ex",
            "lib/ash_authentication/strategies/oauth2/identity_change.ex",
            "lib/ash_authentication/strategies/dynamic_oidc/identity_change.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:resolve/3"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.UserResolver\u0027:email_trusted?/2"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.SignInPreparation\u0027:prepare/3"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.OAuth2.IdentityChange\u0027:change/3"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.DynamicOidc.IdentityChange\u0027:change/3"
            }
          ],
          "repo": "https://github.com/team-alembic/ash_authentication",
          "vendor": "team-alembic",
          "versions": [
            {
              "changes": [
                {
                  "at": "738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459",
                  "status": "unaffected"
                },
                {
                  "at": "2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba",
                  "status": "unaffected"
                }
              ],
              "lessThan": "*",
              "status": "affected",
              "version": "64530644f9b37ebb76ca14aeb83a77597a0034b7",
              "versionType": "git"
            },
            {
              "changes": [
                {
                  "at": "738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459",
                  "status": "unaffected"
                },
                {
                  "at": "2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba",
                  "status": "unaffected"
                }
              ],
              "lessThan": "*",
              "status": "affected",
              "version": "42edcd8ebb13fafbb168f12591d7518ce0611fec",
              "versionType": "git"
            }
          ]
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Improper Authentication vulnerability in team-alembic AshAuthentication allows an attacker to be signed in as another user by linking an OAuth2 identity to an account that is not theirs.\n\nAshAuthentication.Strategy.OAuth2.UserResolver.resolve/3 matches an existing account using the register action\u0027s upsert_identity keys, then gates linking the incoming provider identity to it on email_trusted?/2, which reads only the provider\u0027s email_verified boolean and never compares the provider\u0027s email value with the matched account\u0027s email. That gate assumes the account was matched by its email field, so under any other upsert_identity it is vacuous and an attacker presenting their own verified email is attached to, and issued a session for, an account matched on some other attribute. The same unguarded gate applies in OAuth2.SignInPreparation on the registration_enabled? false path, where the account is matched by the sign-in action\u0027s read filter instead. The upsert also rewrites the matched account\u0027s email to the attacker\u0027s address, so later account recovery reaches the attacker rather than the owner.\n\nThis issue affects ash_authentication: from 4.14.0 before 4.15.0 and from 5.0.0-rc.10 before 5.0.0-rc.14."
    }
  ],
  "id": "CVE-2026-88952",
  "lastModified": "2026-09-18T18:16:18.527",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.1,
          "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:P/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-88952",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-17T19:32:22.090404Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-17T15:16:56.290",
  "references": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://cna.erlef.org/cves/CVE-2026-88952.html"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/commit/2bd630eef8b7c8ae1e90e8fd43ba12fbc7e256ba"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/commit/42edcd8ebb13fafbb168f12591d7518ce0611fec"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/commit/64530644f9b37ebb76ca14aeb83a77597a0034b7"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/commit/738bf9f32f2aa0d1bb92ce9ca5c2476cb5710459"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-wc6x-276q-jrf9"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-88952"
    }
  ],
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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

JSON
How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Loading timeline…




    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.