{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-81638",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-08T14:44:11.859893Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-08T14:44:19.138Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:ash-project:ash_double_entry:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.AshDoubleEntry.ULID\u0027"
          ],
          "packageName": "ash_double_entry",
          "packageURL": "pkg:hex/ash_double_entry",
          "product": "ash_double_entry",
          "programFiles": [
            "lib/ulid.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.AshDoubleEntry.ULID\u0027:cast_input/2"
            },
            {
              "name": "\u0027Elixir.AshDoubleEntry.ULID\u0027:dump_to_native/2"
            }
          ],
          "repo": "https://github.com/ash-project/ash_double_entry",
          "vendor": "ash-project",
          "versions": [
            {
              "lessThan": "1.0.19",
              "status": "affected",
              "version": "0.1.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:ash-project:ash_double_entry:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.AshDoubleEntry.ULID\u0027"
          ],
          "packageName": "ash-project/ash_double_entry",
          "packageURL": "pkg:github/ash-project/ash_double_entry",
          "product": "ash_double_entry",
          "programFiles": [
            "lib/ulid.ex"
          ],
          "programRoutines": [
            {
              "name": "\u0027Elixir.AshDoubleEntry.ULID\u0027:cast_input/2"
            },
            {
              "name": "\u0027Elixir.AshDoubleEntry.ULID\u0027:dump_to_native/2"
            }
          ],
          "repo": "https://github.com/ash-project/ash_double_entry",
          "vendor": "ash-project",
          "versions": [
            {
              "lessThan": "d3e688d300a581ae214b3ca7d95ef4de63fbb050",
              "status": "affected",
              "version": "1e5f7ce8ff25f519c904731a29eb1258324e561a",
              "versionType": "git"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eReachable only when an application exposes \u003ccode\u003eAshDoubleEntry.ULID\u003c/code\u003e as a public identifier over an HTTP or API boundary and performs string-level checks on the submitted ID (idempotency or deduplication keys, deny-lists, audit correlation, or signatures) rather than treating the value as opaque.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Reachable only when an application exposes `AshDoubleEntry.ULID` as a public identifier over an HTTP or API boundary and performs string-level checks on the submitted ID (idempotency or deduplication keys, deny-lists, audit correlation, or signatures) rather than treating the value as opaque."
            }
          ],
          "value": "Reachable only when an application exposes AshDoubleEntry.ULID as a public identifier over an HTTP or API boundary and performs string-level checks on the submitted ID (idempotency or deduplication keys, deny-lists, audit correlation, or signatures) rather than treating the value as opaque."
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:ash-project:ash_double_entry:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.0.19",
                  "versionStartIncluding": "0.1.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ],
          "operator": "AND"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Peter Ullrich"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Peter Ullrich"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Zach Daniel / Ash Project"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Jonatan M\u00e4nnchen / EEF"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eImproper Handling of Alternate Encoding vulnerability in ash-project ash_double_entry allows an attacker to submit several distinct string spellings of the same identifier.\u003c/p\u003e\n\u003cp\u003e\u003ccode\u003eAshDoubleEntry.ULID\u003c/code\u003e renders a 128-bit ULID as 26 Crockford base-32 characters, but the first character encodes only 3 bits, so canonical values are \u003ccode\u003e0\u003c/code\u003e to \u003ccode\u003e7\u003c/code\u003e. \u003ccode\u003edecode/1\u003c/code\u003e in \u003ccode\u003elib/ulid.ex\u003c/code\u003e masks the first character to its low 3 bits and \u003ccode\u003evalid?/1\u003c/code\u003e accepts all 32 characters in that position, so \u003ccode\u003e0...\u003c/code\u003e, \u003ccode\u003e8...\u003c/code\u003e, \u003ccode\u003eG...\u003c/code\u003e and \u003ccode\u003eR...\u003c/code\u003e decode to the identical 16-byte value and resolve to the same row. When the type is exposed as a public ID over an HTTP or API boundary, an attacker-supplied ID can be spelled differently from the record it actually reads or writes, desynchronizing or bypassing string-level checks such as idempotency and deduplication keys, deny-lists, audit correlation, or signatures computed over the submitted ID.\u003c/p\u003e\n\u003cp\u003eThis issue affects ash_double_entry: from 0.1.0 before 1.0.19.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Improper Handling of Alternate Encoding vulnerability in ash-project ash_double_entry allows an attacker to submit several distinct string spellings of the same identifier.\n\n`AshDoubleEntry.ULID` renders a 128-bit ULID as 26 Crockford base-32 characters, but the first character encodes only 3 bits, so canonical values are `0` to `7`. `decode/1` in `lib/ulid.ex` masks the first character to its low 3 bits and `valid?/1` accepts all 32 characters in that position, so `0...`, `8...`, `G...` and `R...` decode to the identical 16-byte value and resolve to the same row. When the type is exposed as a public ID over an HTTP or API boundary, an attacker-supplied ID can be spelled differently from the record it actually reads or writes, desynchronizing or bypassing string-level checks such as idempotency and deduplication keys, deny-lists, audit correlation, or signatures computed over the submitted ID.\n\nThis issue affects ash_double_entry: from 0.1.0 before 1.0.19."
            }
          ],
          "value": "Improper Handling of Alternate Encoding vulnerability in ash-project ash_double_entry allows an attacker to submit several distinct string spellings of the same identifier.\n\nAshDoubleEntry.ULID renders a 128-bit ULID as 26 Crockford base-32 characters, but the first character encodes only 3 bits, so canonical values are 0 to 7. decode/1 in lib/ulid.ex masks the first character to its low 3 bits and valid?/1 accepts all 32 characters in that position, so 0..., 8..., G... and R... decode to the identical 16-byte value and resolve to the same row. When the type is exposed as a public ID over an HTTP or API boundary, an attacker-supplied ID can be spelled differently from the record it actually reads or writes, desynchronizing or bypassing string-level checks such as idempotency and deduplication keys, deny-lists, audit correlation, or signatures computed over the submitted ID.\n\nThis issue affects ash_double_entry: from 0.1.0 before 1.0.19."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-267",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-267 Leverage Alternate Encoding"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 2.1,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "LOW",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-173",
              "description": "CWE-173 Improper Handling of Alternate Encoding",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-07T22:33:29.297Z",
        "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "shortName": "EEF"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory",
            "related"
          ],
          "url": "https://github.com/ash-project/ash_double_entry/security/advisories/GHSA-qxp2-vgp9-268q"
        },
        {
          "tags": [
            "related"
          ],
          "url": "https://cna.erlef.org/cves/CVE-2026-81638.html"
        },
        {
          "tags": [
            "related"
          ],
          "url": "https://osv.dev/vulnerability/EEF-CVE-2026-81638"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/ash-project/ash_double_entry/commit/d3e688d300a581ae214b3ca7d95ef4de63fbb050"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Non-canonical ULID spellings are accepted and alias to the same record in ash_double_entry"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
    "assignerShortName": "EEF",
    "cveId": "CVE-2026-81638",
    "datePublished": "2026-09-07T22:33:29.297Z",
    "dateReserved": "2026-09-07T19:30:01.624Z",
    "dateUpdated": "2026-09-08T14:44:19.138Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}