CVE-2026-86696 Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-86696?
CVE-2026-86696 is a high-severity vulnerability in arekinath esaml, published on 22 Oct 2026.
Official 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.
Weakness: CWE-770
Which versions are affected by CVE-2026-86696?
1 open source package ship an affected version, including esaml.
| Package | Affected | Fixed in |
|---|---|---|
esaml Hex | From 0.1.0 | None |
How do I fix CVE-2026-86696?
No fix has been published for CVE-2026-86696 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-86696 being exploited?
There is no known exploitation of CVE-2026-86696 in the wild and no public exploit code.
Sources
Also known as EEF-CVE-2026-86696, GHSA-5rc7-wrfq-2h25.