{"id":"CVE-2026-82735","state":"PUBLISHED","title":"Match regex runs on over-length input in Ash.Type.String, enabling regex denial of service","description":"Uncontrolled Resource Consumption vulnerability in ash-project ash allows an attacker to force an expensive regular expression to run on input that a length constraint should have already rejected.\n\nAsh.Type.String.apply_constraints/2 (lib/ash/type/string.ex) evaluated the :match regex regardless of the min_length and max_length constraints on the same attribute. Because the length check did not gate the regex, an over-length value that the length constraint rejects still had the pattern applied to it, so the length limit that would otherwise bound the work never constrained the regex input. Against a backtracking pattern this yields catastrophic regex evaluation on attacker-sized input, and even a linear pattern runs on arbitrarily large input, consuming CPU per request. The fix skips the :match regex whenever a length constraint is violated, making the two checks order-independent.\n\nThis issue affects ash: from 0.10.0 before 3.32.2.","publishedAt":"2026-09-01T03:19:36.579Z","updatedAt":"2026-09-01T13:11:14.176Z","severity":{"score":5.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"EEF"},"assigner":"EEF","products":["ash-project ash"],"affected":[{"vendor":"ash-project","product":"ash","packageName":"ash","packageURL":"pkg:hex/ash","defaultStatus":"unaffected","versions":[{"version":"0.10.0","status":"affected","lessThan":"3.32.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Type.String'"],"programFiles":["lib/ash/type/string.ex"],"programRoutines":[{"name":"'Elixir.Ash.Type.String':apply_constraints/2"}],"repo":"https://github.com/ash-project/ash"},{"vendor":"ash-project","product":"ash","packageName":"ash-project/ash","packageURL":"pkg:github/ash-project/ash","defaultStatus":"unaffected","versions":[{"version":"05848d5f4affe60fddd812222a18ada080c0813b","status":"affected","lessThan":"14928412a1a94a69c47df8e98920d3a2b09cdec4","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Type.String'"],"programFiles":["lib/ash/type/string.ex"],"programRoutines":[{"name":"'Elixir.Ash.Type.String':apply_constraints/2"}],"repo":"https://github.com/ash-project/ash"}],"references":["https://github.com/ash-project/ash/security/advisories/GHSA-mq7g-pffw-m8xh","https://cna.erlef.org/cves/CVE-2026-82735.html","https://osv.dev/vulnerability/EEF-CVE-2026-82735","https://github.com/ash-project/ash/commit/14928412a1a94a69c47df8e98920d3a2b09cdec4"],"weaknesses":["CWE-400"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/82xxx/CVE-2026-82735.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-82735","state":"PUBLISHED","datePublished":"2026-09-01T03:19:36.579Z","dateUpdated":"2026-09-01T13:11:14.176Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-08-31T00:59:10.001Z"},"containers":{"cna":{"title":"Match regex runs on over-length input in Ash.Type.String, enabling regex denial of service","descriptions":[{"lang":"en","value":"Uncontrolled Resource Consumption vulnerability in ash-project ash allows an attacker to force an expensive regular expression to run on input that a length constraint should have already rejected.\n\nAsh.Type.String.apply_constraints/2 (lib/ash/type/string.ex) evaluated the :match regex regardless of the min_length and max_length constraints on the same attribute. Because the length check did not gate the regex, an over-length value that the length constraint rejects still had the pattern applied to it, so the length limit that would otherwise bound the work never constrained the regex input. Against a backtracking pattern this yields catastrophic regex evaluation on attacker-sized input, and even a linear pattern runs on arbitrarily large input, consuming CPU per request. The fix skips the :match regex whenever a length constraint is violated, making the two checks order-independent.\n\nThis issue affects ash: from 0.10.0 before 3.32.2."}],"affected":[{"vendor":"ash-project","product":"ash","packageName":"ash","packageURL":"pkg:hex/ash","defaultStatus":"unaffected","versions":[{"version":"0.10.0","status":"affected","lessThan":"3.32.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Type.String'"],"programFiles":["lib/ash/type/string.ex"],"programRoutines":[{"name":"'Elixir.Ash.Type.String':apply_constraints/2"}],"repo":"https://github.com/ash-project/ash"},{"vendor":"ash-project","product":"ash","packageName":"ash-project/ash","packageURL":"pkg:github/ash-project/ash","defaultStatus":"unaffected","versions":[{"version":"05848d5f4affe60fddd812222a18ada080c0813b","status":"affected","lessThan":"14928412a1a94a69c47df8e98920d3a2b09cdec4","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Type.String'"],"programFiles":["lib/ash/type/string.ex"],"programRoutines":[{"name":"'Elixir.Ash.Type.String':apply_constraints/2"}],"repo":"https://github.com/ash-project/ash"}],"references":[{"url":"https://github.com/ash-project/ash/security/advisories/GHSA-mq7g-pffw-m8xh","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-82735.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82735","tags":["related"]},{"url":"https://github.com/ash-project/ash/commit/14928412a1a94a69c47df8e98920d3a2b09cdec4","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"LOCAL","baseScore":5.9,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","description":"CWE-400 Uncontrolled Resource Consumption","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-09-01T03:19:36.579Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*","versionEndExcluding":"3.32.2","versionStartIncluding":"0.10.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"},{"lang":"en","type":"remediation developer","value":"Zach Daniel / Ash Project"},{"lang":"en","type":"reporter","value":"Peter Ullrich"},{"lang":"en","type":"finder","value":"Peter Ullrich"}],"impacts":[{"capecId":"CAPEC-492","descriptions":[{"lang":"en","value":"CAPEC-492 Regular Expression Exponential Blowup"}]}],"source":{"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/ash-project/ash/security/advisories/GHSA-mq7g-pffw-m8xh","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-01T13:10:30.868246Z","id":"CVE-2026-82735","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-01T13:11:14.176Z"}}]}}}