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High · 8.7 CVE-2026-47074 EEF-CVE-2026-47074EUVD-2026-32861GHSA-8jgf-23q5-x7xx

ex_aws_sns SigningCertURL not validated in verify_message/1

Published May 28, 2026 · Updated May 29, 2026 · Assigned by EEF

Description

Improper Certificate Validation vulnerability in ex-aws ex_aws_sns (ExAws.SNS, ExAws.SNS.PublicKeyCache modules) allows Signature Spoofing by Improper Validation.

This vulnerability is associated with program files lib/ex_aws/sns.ex, lib/ex_aws/sns/public_key_cache.ex and program routines 'Elixir.ExAws.SNS':verify_message/1, 'Elixir.ExAws.SNS.PublicKeyCache':get/1.

'Elixir.ExAws.SNS':verify_message/1 fetches the signing certificate from the SigningCertURL field of the incoming SNS message without validating that the URL uses HTTPS or that the host matches an AWS-owned SNS certificate domain. An unauthenticated attacker who can POST to an endpoint that calls verify_message/1 can supply an attacker-controlled SigningCertURL, sign a forged SNS message with their own key, and cause the function to return :ok, completely bypassing SNS signature verification.

This issue affects ex_aws_sns: from 2.0.1 before 2.3.5.

Affected products

VendorProductAffectedFixed
ex-aws ex_aws_sns 2.0.1 – < 2.3.5 2.3.5

Affected packages

EcosystemPackageAffectedFixedRecord
Hex ex_aws_sns >= 2.0.1, < 2.3.5 2.3.5 EEF-CVE-2026-47074

References