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CVE PROGRAM SOURCE RECORD8.7 High

CVE-2026-93471

Unbounded SAML message decompression in esaml allows memory exhaustion

Read JSON ↗CVE.org ↗
Status
Published
Published
Updated
Assigning organization
EEF

Description

Improper Handling of Highly Compressed Data (Data Amplification) in esaml_binding in dropbox esaml allows an unauthenticated attacker to exhaust server memory and crash the Erlang VM via a crafted compressed SAMLResponse. esaml_binding:decode_response/2 base64-decodes the attacker-supplied SAMLResponse, inflates it with zlib:unzip/1 with no bound on the output, then converts the result to a charlist with binary_to_list/1 before parsing. This runs on the SAML consume (ACS) and single-logout endpoints, which accept unauthenticated requests by design, and it runs before any signature check. A small deflate stream reaches a compression ratio near 1000 to 1, so a request body of tens of kilobytes inflates to hundreds of megabytes and then to several gigabytes of list heap, so a few requests exhaust memory and take the node down. This issue affects esaml: from 0.1.0 onward.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

handnot2 esaml

Default version status: unaffected

  • deeb84378d5c82153b470e99d24f77c38afca14a to < *affected
pkg:github/handnot2/esaml

arekinath esaml

Default version status: unaffected

  • deeb84378d5c82153b470e99d24f77c38afca14a to < *affected
pkg:github/arekinath/esaml

dropbox esaml

Default version status: unaffected

  • 0.1.0 to < *affected
pkg:hex/esaml

dropbox esaml

Default version status: unaffected

  • deeb84378d5c82153b470e99d24f77c38afca14a to < *affected
pkg:github/dropbox/esaml

References