{"id":"CVE-2026-82743","state":"PUBLISHED","title":"Ash.Actions.Read.AsyncLimiter busy-spins a scheduler while awaiting slow async reads","description":"Uncontrolled Resource Consumption vulnerability in ash-project ash lets a slow asynchronous read spin a scheduler thread at full CPU while the framework waits for it.\n\nAsh.Actions.Read.AsyncLimiter.await_at_least_one/1 (lib/ash/actions/read/async_limiter.ex) waited for concurrent async read tasks by polling each with Task.yield(task, 0) in a tight loop rather than blocking. While every outstanding task is still running (a slow related-data load or calculation), the loop returns immediately and repeats, busy-spinning and holding a BEAM scheduler at full CPU for the whole duration of the slow read; concurrent slow reads tie up further schedulers. The fix waits with Task.yield_many (a non-blocking sweep followed by a blocking wait with timeout: :infinity), so the process sleeps until a task completes instead of spinning.\n\nThis issue affects ash: from 2.19.0 before 3.32.2.","publishedAt":"2026-09-01T03:37:24.292Z","updatedAt":"2026-09-01T12:40:17.592Z","severity":{"score":2.1,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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":"2.19.0","status":"affected","lessThan":"3.32.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Actions.Read.AsyncLimiter'"],"programFiles":["lib/ash/actions/read/async_limiter.ex"],"programRoutines":[{"name":"'Elixir.Ash.Actions.Read.AsyncLimiter':await_at_least_one/1"}],"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":"c48cb08026cf56b1ac33209203bc9c00061b40b8","status":"affected","lessThan":"0a5ecd2ffdfa848afdeb8827f02982ef2a63a1cd","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Actions.Read.AsyncLimiter'"],"programFiles":["lib/ash/actions/read/async_limiter.ex"],"programRoutines":[{"name":"'Elixir.Ash.Actions.Read.AsyncLimiter':await_at_least_one/1"}],"repo":"https://github.com/ash-project/ash"}],"references":["https://github.com/ash-project/ash/security/advisories/GHSA-33wq-x3q2-c92h","https://cna.erlef.org/cves/CVE-2026-82743.html","https://osv.dev/vulnerability/EEF-CVE-2026-82743","https://github.com/ash-project/ash/commit/0a5ecd2ffdfa848afdeb8827f02982ef2a63a1cd"],"weaknesses":["CWE-400"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/82xxx/CVE-2026-82743.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-82743","state":"PUBLISHED","datePublished":"2026-09-01T03:37:24.292Z","dateUpdated":"2026-09-01T12:40:17.592Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-08-31T01:00:09.774Z"},"containers":{"cna":{"title":"Ash.Actions.Read.AsyncLimiter busy-spins a scheduler while awaiting slow async reads","descriptions":[{"lang":"en","value":"Uncontrolled Resource Consumption vulnerability in ash-project ash lets a slow asynchronous read spin a scheduler thread at full CPU while the framework waits for it.\n\nAsh.Actions.Read.AsyncLimiter.await_at_least_one/1 (lib/ash/actions/read/async_limiter.ex) waited for concurrent async read tasks by polling each with Task.yield(task, 0) in a tight loop rather than blocking. While every outstanding task is still running (a slow related-data load or calculation), the loop returns immediately and repeats, busy-spinning and holding a BEAM scheduler at full CPU for the whole duration of the slow read; concurrent slow reads tie up further schedulers. The fix waits with Task.yield_many (a non-blocking sweep followed by a blocking wait with timeout: :infinity), so the process sleeps until a task completes instead of spinning.\n\nThis issue affects ash: from 2.19.0 before 3.32.2."}],"affected":[{"vendor":"ash-project","product":"ash","packageName":"ash","packageURL":"pkg:hex/ash","defaultStatus":"unaffected","versions":[{"version":"2.19.0","status":"affected","lessThan":"3.32.2","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Actions.Read.AsyncLimiter'"],"programFiles":["lib/ash/actions/read/async_limiter.ex"],"programRoutines":[{"name":"'Elixir.Ash.Actions.Read.AsyncLimiter':await_at_least_one/1"}],"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":"c48cb08026cf56b1ac33209203bc9c00061b40b8","status":"affected","lessThan":"0a5ecd2ffdfa848afdeb8827f02982ef2a63a1cd","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*"],"modules":["'Elixir.Ash.Actions.Read.AsyncLimiter'"],"programFiles":["lib/ash/actions/read/async_limiter.ex"],"programRoutines":[{"name":"'Elixir.Ash.Actions.Read.AsyncLimiter':await_at_least_one/1"}],"repo":"https://github.com/ash-project/ash"}],"references":[{"url":"https://github.com/ash-project/ash/security/advisories/GHSA-33wq-x3q2-c92h","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-82743.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82743","tags":["related"]},{"url":"https://github.com/ash-project/ash/commit/0a5ecd2ffdfa848afdeb8827f02982ef2a63a1cd","tags":["patch"]}],"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":"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:L/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"LOW","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":"2026-09-01T03:37:24.292Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ash-project:ash:*:*:*:*:*:*:*:*","versionEndExcluding":"3.32.2","versionStartIncluding":"2.19.0","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"remediation developer","value":"Zach Daniel / Ash Project"},{"lang":"en","type":"reporter","value":"Peter Ullrich"},{"lang":"en","type":"coordinator","value":"Jonatan Männchen / EEF"},{"lang":"en","type":"finder","value":"Peter Ullrich"}],"impacts":[{"capecId":"CAPEC-227","descriptions":[{"lang":"en","value":"CAPEC-227 Sustained Client Engagement"}]}],"source":{"discovery":"EXTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/ash-project/ash/security/advisories/GHSA-33wq-x3q2-c92h","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-01T12:39:40.600101Z","id":"CVE-2026-82743","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":"2026-09-01T12:40:17.592Z"}}]}}}