FKIE_CVE-2026-66882

Vulnerability from fkie_nvd - Published: 2026-08-25 08:18 - Updated: 2026-09-01 21:15
Severity
2.1 (Low) - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Summary
Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in team-alembic AshAuthentication allows reflected cross-site scripting via the confirmation and magic link interaction forms. When a strategy is configured with require_interaction? set to true, AshAuthentication serves an intermediate HTML page asking the user to confirm the action by submitting a form. Both such pages embed a request parameter directly into a hidden input's value attribute without HTML escaping: lib/ash_authentication/add_ons/confirmation/confirmation_form.html.eex interpolates the confirm parameter, and lib/ash_authentication/strategies/magic_link/sign_in_form.html.eex interpolates the magic link token parameter. These templates are compiled with EEx.function_from_file/3 using plain <%= %> expressions, which perform no escaping, so the parameter is reflected verbatim. Neither accept handler validates the value before rendering it. AshAuthentication.AddOn.Confirmation.Plug.accept/2 only checks that a confirm key is present, and AshAuthentication.Strategy.MagicLink.Plug.accept/2 reads the parameter directly, so no token signature is verified at this stage and arbitrary attacker-supplied text reaches the template. An unauthenticated attacker can therefore craft a URL whose parameter terminates the attribute and injects markup, for example a quote followed by a <script> element. Because the accept phase is served over GET, loading the crafted link is sufficient; no form submission or prior authentication is required. The injected script executes in the origin of the application embedding AshAuthentication, giving it access to that origin's cookies, session, and same-origin responses. Since these pages are part of the authentication flow, a victim following what appears to be a legitimate confirmation or sign-in link is a plausible target. This issue affects ash_authentication: from 4.8.0 before 4.14.2 and from 5.0.0-rc.0 before 5.0.0-rc.13.
References
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://cna.erlef.org/cves/CVE-2026-66882.html
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/commit/0bd5199db066be22b2ca1ec8bc6109e5d62e6070
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/commit/62719710790a150a9eacab9c0a066e0d122d15be
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/team-alembic/ash_authentication/security/advisories/GHSA-54fc-x3hv-ffhw
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://osv.dev/vulnerability/EEF-CVE-2026-66882
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-54fc-x3hv-ffhw
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.MagicLink.Plug\u0027",
            "\u0027Elixir.AshAuthentication.AddOn.Confirmation.Plug\u0027"
          ],
          "packageName": "ash_authentication",
          "packageURL": "pkg:hex/ash_authentication",
          "product": "ash_authentication",
          "programFiles": [
            "lib/ash_authentication/strategies/magic_link/sign_in_form.html.eex",
            "lib/ash_authentication/strategies/magic_link/plug.ex",
            "lib/ash_authentication/add_ons/confirmation/confirmation_form.html.eex",
            "lib/ash_authentication/add_ons/confirmation/plug.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.MagicLink.Plug\u0027:accept/2"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.AddOn.Confirmation.Plug\u0027:accept/2"
            }
          ],
          "repo": "https://github.com/team-alembic/ash_authentication",
          "vendor": "team-alembic",
          "versions": [
            {
              "lessThan": "4.14.2",
              "status": "affected",
              "version": "4.8.0",
              "versionType": "semver"
            },
            {
              "lessThan": "5.0.0-rc.13",
              "status": "affected",
              "version": "5.0.0-rc.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.AshAuthentication.Strategy.MagicLink.Plug\u0027",
            "\u0027Elixir.AshAuthentication.AddOn.Confirmation.Plug\u0027"
          ],
          "packageName": "team-alembic/ash_authentication",
          "packageURL": "pkg:github/team-alembic/ash_authentication",
          "product": "ash_authentication",
          "programFiles": [
            "lib/ash_authentication/strategies/magic_link/sign_in_form.html.eex",
            "lib/ash_authentication/strategies/magic_link/plug.ex",
            "lib/ash_authentication/add_ons/confirmation/confirmation_form.html.eex",
            "lib/ash_authentication/add_ons/confirmation/plug.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.AshAuthentication.Strategy.MagicLink.Plug\u0027:accept/2"
            },
            {
              "name": "\u0027Elixir.AshAuthentication.AddOn.Confirmation.Plug\u0027:accept/2"
            }
          ],
          "repo": "https://github.com/team-alembic/ash_authentication",
          "vendor": "team-alembic",
          "versions": [
            {
              "changes": [
                {
                  "at": "62719710790a150a9eacab9c0a066e0d122d15be",
                  "status": "unaffected"
                },
                {
                  "at": "0bd5199db066be22b2ca1ec8bc6109e5d62e6070",
                  "status": "unaffected"
                }
              ],
              "lessThan": "*",
              "status": "affected",
              "version": "fe0b4558dbe852fee5d81a460a8355577618a8c8",
              "versionType": "git"
            }
          ]
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in team-alembic AshAuthentication allows reflected cross-site scripting via the confirmation and magic link interaction forms.\n\nWhen a strategy is configured with require_interaction? set to true, AshAuthentication serves an intermediate HTML page asking the user to confirm the action by submitting a form. Both such pages embed a request parameter directly into a hidden input\u0027s value attribute without HTML escaping: lib/ash_authentication/add_ons/confirmation/confirmation_form.html.eex interpolates the confirm parameter, and lib/ash_authentication/strategies/magic_link/sign_in_form.html.eex interpolates the magic link token parameter. These templates are compiled with EEx.function_from_file/3 using plain \u003c%= %\u003e expressions, which perform no escaping, so the parameter is reflected verbatim.\n\nNeither accept handler validates the value before rendering it. AshAuthentication.AddOn.Confirmation.Plug.accept/2 only checks that a confirm key is present, and AshAuthentication.Strategy.MagicLink.Plug.accept/2 reads the parameter directly, so no token signature is verified at this stage and arbitrary attacker-supplied text reaches the template. An unauthenticated attacker can therefore craft a URL whose parameter terminates the attribute and injects markup, for example a quote followed by a \u003cscript\u003e element. Because the accept phase is served over GET, loading the crafted link is sufficient; no form submission or prior authentication is required.\n\nThe injected script executes in the origin of the application embedding AshAuthentication, giving it access to that origin\u0027s cookies, session, and same-origin responses. Since these pages are part of the authentication flow, a victim following what appears to be a legitimate confirmation or sign-in link is a plausible target.\n\nThis issue affects ash_authentication: from 4.8.0 before 4.14.2 and from 5.0.0-rc.0 before 5.0.0-rc.13."
    }
  ],
  "id": "CVE-2026-66882",
  "lastModified": "2026-09-01T21:15:00.147",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 2.1,
          "baseSeverity": "LOW",
          "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": "LOW",
          "subIntegrityImpact": "LOW",
          "userInteraction": "ACTIVE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-66882",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-25T19:50:10.506279Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-25T08:18:10.143",
  "references": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://cna.erlef.org/cves/CVE-2026-66882.html"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/commit/0bd5199db066be22b2ca1ec8bc6109e5d62e6070"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/commit/62719710790a150a9eacab9c0a066e0d122d15be"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-54fc-x3hv-ffhw"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-66882"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-54fc-x3hv-ffhw"
    }
  ],
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary"
    }
  ]
}



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