CVE-2026-47074

ex_aws_sns SigningCertURL not validated in verify_message/1

HIGH
8.7
CVSS Score
Published: May 28, 2026 at 09:05 AM UTC
Updated: October 26, 2026 at 11:10 AM UTC
2 products affected across 2 vendorsex_aws_snsSns

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Severity
HIGH8.7
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.0.1 ≤ v < 2.3.52.0.1a7ec21880943f4dac1d59bda557db0ffcd2b61fa
Vendor states this is fixed in 1853d280b152d10384a1e21a22cf22152a60be48 (fixed)
Affected range stops below 2.3.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHEEF
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-295

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