CVE-2026-93471: fallo de gravedad alta en arekinath esaml
Unbounded SAML message decompression in esaml allows memory exhaustion
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
21Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 8.7epss 0.7%
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.
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
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Referencias
https://cna.erlef.org/cves/CVE-2026-93471.htmlhttps://github.com/arekinath/esaml/commit/deeb84378d5c82153b470e99d24f77c38afca14ahttps://github.com/dropbox/esaml/commit/deeb84378d5c82153b470e99d24f77c38afca14ahttps://github.com/handnot2/esaml/commit/deeb84378d5c82153b470e99d24f77c38afca14ahttps://osv.dev/vulnerability/EEF-CVE-2026-93471