# CVE-2026-86696: Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion

> CVE-2026-86696: Unbounded atom creation from unsigned LogoutResponse status codes in esaml allows atom table exhaustion. CVSS 8.2 (CVSS 4.0).

Canonical: https://rewindex.com/cve/CVE-2026-86696
Last updated: 2026-10-22T16:58:51Z

- Published: 2026-10-22 06:59 UTC · Updated: 2026-10-22 16:58 UTC · Assigner: EEF
- CVSS: 8.2 (CVSS 4.0) · Severity: High
- EPSS: 0.44%, 38th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-770

## 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 vendors and products

- arekinath: esaml
- dropbox: esaml
- handnot2: esaml

## Tracked companies

- [Dropbox](https://rewindex.com/company/dropbox.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-86696)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-86696)
- [https://cna.erlef.org/cves/CVE-2026-86696.html](https://cna.erlef.org/cves/CVE-2026-86696.html)
- [https://github.com/arekinath/esaml/commit/be692b56245071899757afa7ef47e43593d3de96](https://github.com/arekinath/esaml/commit/be692b56245071899757afa7ef47e43593d3de96)
- [https://github.com/dropbox/esaml/commit/be692b56245071899757afa7ef47e43593d3de96](https://github.com/dropbox/esaml/commit/be692b56245071899757afa7ef47e43593d3de96)
- [https://github.com/handnot2/esaml/commit/be692b56245071899757afa7ef47e43593d3de96](https://github.com/handnot2/esaml/commit/be692b56245071899757afa7ef47e43593d3de96)
- [https://osv.dev/vulnerability/EEF-CVE-2026-86696](https://osv.dev/vulnerability/EEF-CVE-2026-86696)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-86696 · Markdown: https://rewindex.com/cve/CVE-2026-86696.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-86696 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:11:16.124Z