{"containers":{"cna":{"affected":[{"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash_double_entry:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["'Elixir.AshDoubleEntry.ULID'"],"packageName":"ash_double_entry","packageURL":"pkg:hex/ash_double_entry","product":"ash_double_entry","programFiles":["lib/ulid.ex"],"programRoutines":[{"name":"'Elixir.AshDoubleEntry.ULID':cast_input/2"},{"name":"'Elixir.AshDoubleEntry.ULID':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":["'Elixir.AshDoubleEntry.ULID'"],"packageName":"ash-project/ash_double_entry","packageURL":"pkg:github/ash-project/ash_double_entry","product":"ash_double_entry","programFiles":["lib/ulid.ex"],"programRoutines":[{"name":"'Elixir.AshDoubleEntry.ULID':cast_input/2"},{"name":"'Elixir.AshDoubleEntry.ULID':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":"<p>Reachable only when an application exposes <code>AshDoubleEntry.ULID</code> 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.</p>"},{"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 Männchen / EEF"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>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.</p>\n<p><code>AshDoubleEntry.ULID</code> renders a 128-bit ULID as 26 Crockford base-32 characters, but the first character encodes only 3 bits, so canonical values are <code>0</code> to <code>7</code>. <code>decode/1</code> in <code>lib/ulid.ex</code> masks the first character to its low 3 bits and <code>valid?/1</code> accepts all 32 characters in that position, so <code>0...</code>, <code>8...</code>, <code>G...</code> and <code>R...</code> 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.</p>\n<p>This issue affects ash_double_entry: from 0.1.0 before 1.0.19.</p>"},{"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":"2026-09-07T22:33:29.297Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"}