{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "web-token/jwt-library"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.4.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "web-token/jwt-framework"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "4.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "web-token/jwt-library"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "web-token/jwt-library"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.1.0"
            },
            {
              "fixed": "4.1.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-400",
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-18T21:09:01Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\n\nWhen a JWE uses a password-based key-encryption algorithm (`PBES2-HS256+A128KW`, `PBES2-HS384+A192KW`, `PBES2-HS512+A256KW`), `PBES2AESKW::unwrapKey()` reads the `p2c` (PBKDF2 iteration count) parameter directly from the attacker-controlled JOSE header and passes it to `hash_pbkdf2()` with **no upper bound**. The only validation performed (`checkHeaderAdditionalParameters()`) was `is_int($p2c) \u0026\u0026 $p2c \u003e 0`.\n\nAn unauthenticated attacker can craft a single JWE whose protected header sets a very large `p2c` (e.g. `100_000_000` \u2248 87 s of CPU, or `PHP_INT_MAX`), forcing a worker to spend an arbitrary amount of CPU inside PBKDF2 **before** the key unwrap can even fail. The decrypter swallows the eventual exception, so the attacker pays almost nothing while the server burns CPU. JSON General serialization (multiple recipients) and multi-key JWKSets multiply the cost. This is a classic uncontrolled-resource-consumption (CWE-400) denial of service.\n\n### Affected configurations\n\nApplications that register any `PBES2-HS*+A*KW` algorithm in their decryption `AlgorithmManager`.\n\n### Patches\n\n`PBES2AESKW` now enforces a configurable maximum iteration count (`DEFAULT_MAX_COUNT = 1_000_000`, well above realistic legitimate values which are a few thousand) in `checkHeaderAdditionalParameters()`, before any PBKDF2 computation. The bound is exposed as a constructor argument so operators can tune it.\n\n### Workarounds\n\nBefore upgrading: validate/limit the `p2c` header with a custom header checker, or do not enable PBES2 algorithms for untrusted tokens.\n\n### References\n\n- RFC 7518 \u00a74.8 (PBES2)\n- CWE-400: Uncontrolled Resource Consumption\n\n## R\u00e9solution\n\nUn correctif a \u00e9t\u00e9 pr\u00e9par\u00e9 sur une branche d\u00e9di\u00e9e bas\u00e9e sur `3.4.x`, avec des tests anti-r\u00e9gression d\u00e9di\u00e9s (fork priv\u00e9 temporaire de cette advisory, PR #1).\n\n**PBES2** \u2014 `PBES2AESKW::unwrapKey()` borne d\u00e9sormais le param\u00e8tre `p2c` (constante `DEFAULT_MAX_COUNT = 1_000_000`, configurable via le constructeur) avant tout appel \u00e0 `hash_pbkdf2()`, emp\u00eachant l\u0027amplification CPU (DoS).\n\n**Validation :** `php -l` OK, PHPUnit vert, aucune nouvelle erreur PHPStan introduite (diff\u00e9rentiel nul vs `3.4.x`), aucun commentaire ajout\u00e9 dans le code source. Apr\u00e8s merge, cascade pr\u00e9vue `3.4.x \u2192 4.0.x \u2192 4.1.x`.",
  "id": "GHSA-3prj-6hqw-cm82",
  "modified": "2026-06-18T21:09:01Z",
  "published": "2026-06-18T21:09:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/web-token/jwt-framework/security/advisories/GHSA-3prj-6hqw-cm82"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/web-token/jwt-library/GHSA-3prj-6hqw-cm82.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/web-token/jwt-framework"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "PHP JWT Library: PBES2-HS*+A*KW unwrap accepts an unbounded p2c iteration count, enabling CPU-amplification denial of service"
}