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.
Published: 2026-05-28
Score: 8.7 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-jq4m-q6p2-8gwc Hackney: Per-chunk timeout with unbounded body accumulation enables slow-drip OOM
Github GHSA Github GHSA GHSA-8jgf-23q5-x7xx ex_aws_sns: Trusted-attacker `SigningCertURL` permits complete SNS signature bypass
History

Thu, 28 May 2026 11:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 28 May 2026 10:15:00 +0000

Type Values Removed Values Added
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.
Title ex_aws_sns SigningCertURL not validated in verify_message/1
First Time appeared Ex Aws Sns Project
Ex Aws Sns Project ex Aws Sns
Weaknesses CWE-295
CPEs cpe:2.3:a:ex_aws_sns_project:ex_aws_sns:*:*:*:*:*:*:*:*
Vendors & Products Ex Aws Sns Project
Ex Aws Sns Project ex Aws Sns
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


Subscriptions

Ex Aws Sns Project Ex Aws Sns
cve-icon MITRE

Status: PUBLISHED

Assigner: EEF

Published:

Updated: 2026-05-29T04:40:43.232Z

Reserved: 2026-05-18T17:28:08.322Z

Link: CVE-2026-47074

cve-icon Vulnrichment

Updated: 2026-05-28T10:31:09.474Z

cve-icon NVD

Status : Deferred

Published: 2026-05-28T10:16:39.800

Modified: 2026-05-29T15:29:42.387

Link: CVE-2026-47074

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-29T15:48:36Z

Weaknesses