CVE-2026-86696: Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion
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.
CWE-770
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
arekinath: esamldropbox: esamlhandnot2: esaml
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- cna.erlef.org/cves/CVE-2026-86696.html (opens in new tab)
- github.com/arekinath/esaml/commit/be692b56245071899757afa7ef47e43593d3de96 (opens in new tab)
- github.com/dropbox/esaml/commit/be692b56245071899757afa7ef47e43593d3de96 (opens in new tab)
- github.com/handnot2/esaml/commit/be692b56245071899757afa7ef47e43593d3de96 (opens in new tab)
- osv.dev/vulnerability/EEF-CVE-2026-86696 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)