CVE-2026-86696

Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion

HIGH
8.2
CVSS Score
Published: October 22, 2026 at 06:59 AM UTC
Updated: October 22, 2026 at 04:58 PM UTC
3 products affected across 3 vendorsEsamlEsamlEsaml

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Severity
HIGH8.2
Exploit prediction
EPSS 0.4%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

be692b56245071899757afa7ef47e43593d3de96
0.1.0be692b56245071899757afa7ef47e43593d3de96
be692b56245071899757afa7ef47e43593d3de96

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

8.2HIGHEEF
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-770

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