CVE-2026-86696 | BDVDB-2026-394337 Detail
handnot2esaml
Description#
Allocation of Resources Without Limits or Throttling vulnerability in esaml in dropbox esaml allows an unauthenticated attacker to exhaust the Erlang VM atom table and crash the node via unsigned LogoutResponse messages. esaml:status_code_map/1 in src/esaml.erl maps any StatusCode value it does not recognize to an atom with list_to_atom/1 on the last colon-separated segment of the URN. esaml_sp:validate_logout_response/2 verifies a signature only when the message carries one, so an unsigned LogoutResponse posted to the single-logout endpoint reaches esaml:decode_logout_response/1 and mints one permanent atom per distinct status value. Atoms are never reclaimed and the VM caps the atom table at about one million entries, so an attacker who posts that many distinct values aborts the node. This issue affects esaml: from 0.1.0 onward.
Impact#
An unauthenticated attacker posts unsigned LogoutResponse messages with distinct status code URNs to a service provider's single-logout endpoint. Each message permanently consumes one atom table entry, and about one million of them abort the Erlang VM, denying service to every user of the service provider.
Weaknesses#
- CWE-770 Allocation of Resources Without Limits or Throttling
References#
- https://cna.erlef.org/cves/CVE-2026-86696.html
- https://osv.dev/vulnerability/EEF-CVE-2026-86696
- https://github.com/handnot2/esaml/commit/be692b56245071899757afa7ef47e43593d3de96
- https://github.com/arekinath/esaml/commit/be692b56245071899757afa7ef47e43593d3de96
- https://github.com/dropbox/esaml/commit/be692b56245071899757afa7ef47e43593d3de96
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.