{"affected":[{"package":{"ecosystem":"Hex","name":"ash_authentication","purl":"pkg:hex/ash_authentication"},"ranges":[{"events":[{"introduced":"4.8.0"},{"fixed":"4.15.0"}],"type":"SEMVER"},{"events":[{"introduced":"5.0.0-rc.0"},{"fixed":"5.0.0-rc.14"}],"type":"SEMVER"}],"versions":["4.8.0","4.8.1","4.8.2","4.8.3","4.8.5","4.8.6","4.8.7","4.9.0","4.9.1","4.9.2","4.9.3","4.9.4","4.9.5","4.9.6","4.9.7","4.9.8","4.9.9","4.10.0","4.11.0","4.12.0","4.13.0","4.13.1","4.13.2","4.13.3","4.13.4","4.13.5","4.13.6","4.13.7","4.14.0","4.14.1","4.14.2","5.0.0-rc.0","5.0.0-rc.1","5.0.0-rc.2","5.0.0-rc.3","5.0.0-rc.4","5.0.0-rc.5","5.0.0-rc.6","5.0.0-rc.7","5.0.0-rc.8","5.0.0-rc.9","5.0.0-rc.10","5.0.0-rc.11","5.0.0-rc.12","5.0.0-rc.13"]},{"ranges":[{"events":[{"introduced":"f3a53f480088419788d5c3934af3131fa9066773"},{"fixed":"d5a5d4cb5cc17fbd6e2a120a6111b47accad4b8e"},{"fixed":"dfb19c897853686ab481c5e773f7a1a0c74dea04"}],"repo":"https://github.com/team-alembic/ash_authentication","type":"GIT"}]}],"aliases":["GHSA-q876-xr24-2mcx","CVE-2026-82760"],"credits":[{"name":"Peter Ullrich","type":"REPORTER"},{"name":"James Harton","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"ANALYST"}],"database_specific":{"capec_ids":["CAPEC-130"],"cpe_ids":["cpe:2.3:a:team-alembic:ash_authentication:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-407"]},"details":"## Summary\n\nInefficient Algorithmic Complexity vulnerability in team-alembic AshAuthentication allows an unauthenticated attacker to exhaust CPU and memory via an oversized base62 segment in a submitted API key.\n\n`AshAuthentication.Base.decode62/1` in `lib/ash_authentication/base.ex` splits its argument into one binary per character and folds it with `charval62/2`, which recomputes `Integer.pow(62, index)` at every position instead of accumulating by Horner's method, so cost grows roughly cubically in the input length. `bindecode62/1` in the same module is quadratic through `Integer.undigits/2` and `Integer.digits/2`. Neither function caps `byte_size/1`, and `AshAuthentication.Strategy.ApiKey.SignInPreparation` passes the underscore-separated segments of the submitted key straight into both, before any key lookup and without prior authentication. The surrounding `rescue` clauses catch exceptions, not CPU or memory exhaustion.\n\nThis issue affects ash_authentication: from 4.8.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.","id":"EEF-CVE-2026-82760","modified":"2026-09-17T13:08:47.235124Z","published":"2026-09-17T13:08:46.382Z","references":[{"type":"ADVISORY","url":"https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-q876-xr24-2mcx"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-82760.html"},{"type":"WEB","url":"https://github.com/team-alembic/ash_authentication/commit/f3a53f480088419788d5c3934af3131fa9066773"},{"type":"FIX","url":"https://github.com/team-alembic/ash_authentication/commit/d5a5d4cb5cc17fbd6e2a120a6111b47accad4b8e"},{"type":"FIX","url":"https://github.com/team-alembic/ash_authentication/commit/dfb19c897853686ab481c5e773f7a1a0c74dea04"},{"type":"PACKAGE","url":"https://hex.pm/packages/ash_authentication"}],"related":[],"schema_version":"1.7.3","severity":[{"score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","type":"CVSS_V4"}],"summary":"Superlinear base62 decoding exhausts CPU and memory in AshAuthentication API key sign-in","upstream":[]}