# CVE-2026-105270: Dropbox esaml atom table exhaustion in SAMLResponse parsing

Source: https://junglewise.ai/threats/cve-2026-105270-allocation-of-resources-without-limits-or-throttling  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-22. Updated: 2026-10-22  
License: CC BY 4.0 with a link back

CVE-2026-105270 · Severity: info · Published 2026-10-22

Dropbox esaml is a SAML library that handles single sign-on authentication for web applications. An unauthenticated attacker can crash the Erlang virtual machine by sending specially crafted SAML responses to the login endpoints, causing the application to become unavailable. The attack exploits the way the library parses XML without limiting resource consumption.

Technologies: [Dropbox Esaml](https://junglewise.ai/threats/technologies/dropbox-esaml). Vendors: [Dropbox](https://junglewise.ai/threats/vendors/dropbox).

## Quick answers

**Is CVE-2026-105270 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105270 being exploited in the wild.

**How severe is CVE-2026-105270?** Informational severity, published 22 October 2026.

**Which products and versions are affected?** Dropbox Esaml 0.1.0 and later.

**Is there a fix for CVE-2026-105270?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-105270 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-105270?** Check whether you run Dropbox Esaml at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

esaml_binding:decode_response/2 parses SAMLResponse using xmerl_scan:string/2, which interns element names, attributes, and namespace prefixes as permanent atoms in the Erlang VM. Since SAML ACS and logout endpoints process unauthenticated requests before signature verification, an attacker can send a well-formed XML document with thousands of distinct element names within the 128 KB request limit to exhaust the atom table (capped at ~1 million entries), causing VM crash after dozens of requests. This is a denial-of-service via resource exhaustion with network attack vector requiring no authentication.

## Affected products

- Dropbox esaml 0.1.0 and later

## Timeline

- 2026-10-22: disclosed

## References

- [https://github.com/](https://github.com/)
- [https://repo.hex.pm/](https://repo.hex.pm/)

## Related threats

- [Dropbox esaml data amplification denial of service](https://junglewise.ai/threats/cve-2026-93471-improper-handling-of-highly-compressed-data-data-amplification-in)
- [Dropbox esaml unthrottled atom creation in LogoutResponse](https://junglewise.ai/threats/cve-2026-86696-allocation-of-resources-without-limits-or-throttling)