All vulnerabilities
CVE-2026-86696

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

handnot2 esaml
Open in ThreatlineRecord JSON
CVSS
8.2High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.44%Chance of exploitation activity in the next 30 days, higher than 37% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published22 Oct 2026Updated 22 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 2

  • esamlaffected: be692b56245071899757afa7ef47e43593d3de96 and laterCVE List
  • esamlaffected: 0.1.0 and laterCVE List

References 5