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Vulnerability · Published Oct 22, 2026 · Assigned by EEF

CVE-2026-105270Unbounded atom creation while parsing SAML messages in esaml allows atom table exhaustion

High 8.7

In plain English

A high-severity resource allocation without limits in esaml from arekinath. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.5%top 54.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Allocation of Resources Without Limits or Throttling vulnerability in esaml_binding in dropbox esaml allows an unauthenticated attacker to exhaust the Erlang VM atom table and crash the node via a crafted SAMLResponse. esaml_binding:decode_response/2 parses the decoded SAMLResponse with xmerl_scan:string/2, which interns every element name, attribute name, and namespace prefix it reads as a permanent atom. The SAML consume (ACS) and single-logout endpoints call it on unauthenticated requests before any signature check, so one well-formed document with thousands of distinct names mints thousands of atoms while staying inside the 128 KB request body limit. Atoms are never reclaimed and the VM caps the atom table at about one million entries, so a few dozen requests abort the node. This issue affects esaml: from 0.1.0 onward.

Affected products (as reported)

VendorProductVersions
arekinath esaml deeb84378d5c82153b470e99d24f77c38afca14a – before *
handnot2 esaml deeb84378d5c82153b470e99d24f77c38afca14a – before *
dropbox esaml 0.1.0 – before *
dropbox esaml deeb84378d5c82153b470e99d24f77c38afca14a – before *

Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References