CVE-2026-82760
Description
Inefficient 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. 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. This 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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://cna.erlef.org/cves/CVE-2026-82760.html
- https://github.com/team-alembic/ash_authentication/commit/d5a5d4cb5cc17fbd6e2a120a6111b47accad4b8e
- https://github.com/team-alembic/ash_authentication/commit/dfb19c897853686ab481c5e773f7a1a0c74dea04
- https://github.com/team-alembic/ash_authentication/commit/f3a53f480088419788d5c3934af3131fa9066773
- https://github.com/team-alembic/ash_authentication/security/advisories/GHSA-q876-xr24-2mcx
- https://osv.dev/vulnerability/EEF-CVE-2026-82760
CWEs
CWE-407
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.