FKIE_CVE-2026-53431

Vulnerability from fkie_nvd - Published: 2026-07-30 15:16 - Updated: 2026-10-23 22:10
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
Authentication Bypass by Capture-replay vulnerability in malach-it Boruta allows an attacker who has obtained a previously valid JWT client assertion to authenticate as the issuing OAuth client after the assertion has expired. Boruta accepts JWT-based client authentication (client_secret_jwt and private_key_jwt token endpoint authentication methods) but never enforces that the assertion's exp claim is in the future. The pre-check helper Boruta.Oauth.Request.Base.check_expiration/1 in lib/boruta/oauth/request/base.ex only verifies that an exp claim is present (it pattern-matches on the existence of the key and returns success), and the Joken token configuration used for signature verification, Boruta.Oauth.Authorization.Client.Token.token_config/0 in lib/boruta/oauth/authorization/client.ex, returns an empty map, so Joken's default exp claim validator is not engaged either. Any attacker who obtains a validly-signed client assertion (for example through logs, reverse proxies, browser tooling, or other observability surfaces) can replay it indefinitely to authenticate as the client and obtain access tokens with that client's privileges. This issue affects boruta: from 2.3.0 before 2.3.7.
References
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://cna.erlef.org/cves/CVE-2026-53431.html
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/malach-it/boruta_auth/commit/5204f88f9b2cdd9637a755337ed5f99185be5474
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/malach-it/boruta_auth/commit/69363432aa36760fc5438e4e17115d0f7c1b925a
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://github.com/malach-it/boruta_auth/security/advisories/GHSA-xjv8-vmh5-xhf6
6b3ad84c-e1a6-4bf7-a703-f496b71e49dbhttps://osv.dev/vulnerability/EEF-CVE-2026-53431
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/malach-it/boruta_auth/security/advisories/GHSA-xjv8-vmh5-xhf6
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:malach-it:boruta_auth:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.Boruta.Oauth.Request.Base\u0027",
            "\u0027Elixir.Boruta.Oauth.Authorization.Client.Token\u0027"
          ],
          "packageName": "boruta",
          "packageURL": "pkg:hex/boruta",
          "product": "boruta",
          "programFiles": [
            "lib/boruta/oauth/request/base.ex",
            "lib/boruta/oauth/authorization/client.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.Boruta.Oauth.Request.Base\u0027:fetch_client_authentication/1"
            },
            {
              "name": "\u0027Elixir.Boruta.Oauth.Request.Base\u0027:check_expiration/1"
            },
            {
              "name": "\u0027Elixir.Boruta.Oauth.Authorization.Client.Token\u0027:token_config/0"
            }
          ],
          "repo": "https://github.com/malach-it/boruta_auth",
          "vendor": "malach-it",
          "versions": [
            {
              "lessThan": "2.3.7",
              "status": "affected",
              "version": "2.3.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:malach-it:boruta_auth:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.Boruta.Oauth.Request.Base\u0027",
            "\u0027Elixir.Boruta.Oauth.Authorization.Client.Token\u0027"
          ],
          "packageName": "malach-it/boruta_auth",
          "packageURL": "pkg:github/malach-it/boruta_auth",
          "product": "boruta",
          "programFiles": [
            "lib/boruta/oauth/request/base.ex",
            "lib/boruta/oauth/authorization/client.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.Boruta.Oauth.Request.Base\u0027:fetch_client_authentication/1"
            },
            {
              "name": "\u0027Elixir.Boruta.Oauth.Request.Base\u0027:check_expiration/1"
            },
            {
              "name": "\u0027Elixir.Boruta.Oauth.Authorization.Client.Token\u0027:token_config/0"
            }
          ],
          "repo": "https://github.com/malach-it/boruta_auth",
          "vendor": "malach-it",
          "versions": [
            {
              "changes": [
                {
                  "at": "5204f88f9b2cdd9637a755337ed5f99185be5474",
                  "status": "unaffected"
                },
                {
                  "at": "69363432aa36760fc5438e4e17115d0f7c1b925a",
                  "status": "unaffected"
                }
              ],
              "lessThan": "*",
              "status": "affected",
              "version": "5bfbe1c5443bffe71cf1bf954bbdff61327d9a83",
              "versionType": "git"
            }
          ]
        }
      ],
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Authentication Bypass by Capture-replay vulnerability in malach-it Boruta allows an attacker who has obtained a previously valid JWT client assertion to authenticate as the issuing OAuth client after the assertion has expired.\n\nBoruta accepts JWT-based client authentication (client_secret_jwt and private_key_jwt token endpoint authentication methods) but never enforces that the assertion\u0027s exp claim is in the future. The pre-check helper Boruta.Oauth.Request.Base.check_expiration/1 in lib/boruta/oauth/request/base.ex only verifies that an exp claim is present (it pattern-matches on the existence of the key and returns success), and the Joken token configuration used for signature verification, Boruta.Oauth.Authorization.Client.Token.token_config/0 in lib/boruta/oauth/authorization/client.ex, returns an empty map, so Joken\u0027s default exp claim validator is not engaged either. Any attacker who obtains a validly-signed client assertion (for example through logs, reverse proxies, browser tooling, or other observability surfaces) can replay it indefinitely to authenticate as the client and obtain access tokens with that client\u0027s privileges.\n\nThis issue affects boruta: from 2.3.0 before 2.3.7."
    },
    {
      "lang": "es",
      "value": "Una vulnerabilidad de omisi\u00f3n de autenticaci\u00f3n por captura-repetici\u00f3n en malach-it Boruta permite a un atacante que ha obtenido una aserci\u00f3n de cliente JWT previamente v\u00e1lida autenticarse como el cliente OAuth emisor despu\u00e9s de que la aserci\u00f3n haya expirado.\n\nBoruta acepta la autenticaci\u00f3n de cliente basada en JWT (m\u00e9todos de autenticaci\u00f3n de punto final de token client_secret_jwt y private_key_jwt) pero nunca impone que la declaraci\u00f3n \u2019exp\u2019 de la aserci\u00f3n est\u00e9 en el futuro. La funci\u00f3n auxiliar de pre-verificaci\u00f3n Boruta.Oauth.Request.Base.check_expiration/1 en lib/boruta/oauth/request/base.ex solo verifica que una declaraci\u00f3n \u2019exp\u2019 est\u00e9 presente (hace coincidir patrones con la existencia de la clave y devuelve \u00e9xito), y la configuraci\u00f3n de token de Joken utilizada para la verificaci\u00f3n de firma, Boruta.Oauth.Authorization.Client.Token.token_config/0 en lib/boruta/oauth/authorization/client.ex, devuelve un mapa vac\u00edo, por lo que el validador de declaraci\u00f3n \u2019exp\u2019 predeterminado de Joken tampoco se activa. Cualquier atacante que obtenga una aserci\u00f3n de cliente v\u00e1lidamente firmada (por ejemplo, a trav\u00e9s de registros, proxies inversos, herramientas de navegador u otras superficies de observabilidad) puede reproducirla indefinidamente para autenticarse como el cliente y obtener tokens de acceso con los privilegios de ese cliente.\n\nEste problema afecta a boruta: desde 2.3.0 antes de 2.3.7."
    }
  ],
  "id": "CVE-2026-53431",
  "lastModified": "2026-10-23T22:10:00.160",
  "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-2026-53431",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-30T16:12:55.290055Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-30T15:16:33.567",
  "references": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://cna.erlef.org/cves/CVE-2026-53431.html"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/malach-it/boruta_auth/commit/5204f88f9b2cdd9637a755337ed5f99185be5474"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/malach-it/boruta_auth/commit/69363432aa36760fc5438e4e17115d0f7c1b925a"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://github.com/malach-it/boruta_auth/security/advisories/GHSA-xjv8-vmh5-xhf6"
    },
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-53431"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/malach-it/boruta_auth/security/advisories/GHSA-xjv8-vmh5-xhf6"
    }
  ],
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-294"
        }
      ],
      "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.