Vulnerability · Published May 28, 2026 · Assigned by EEF
CVE-2026-47074ex_aws_sns SigningCertURL not validated in verify_message/1
High 8.7
In plain English
A high-severity improper certificate validation in ex_aws_sns from ex-aws. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).
Official 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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ex-aws | ex_aws_sns | 2.0.1 – before 2.3.5 |
| ex-aws | ex_aws_sns | a7ec21880943f4dac1d59bda557db0ffcd2b61fa – before 1853d280b152d10384a1e21a22cf22152a60be48 |
Weakness: CWE-295 · 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
References
- https://github.com/ex-aws/ex_aws_sns/security/advisories/GHSA-8jgf-23q5-x7xx vendor-advisory, related
- https://cna.erlef.org/cves/CVE-2026-47074.html related
- https://osv.dev/vulnerability/EEF-CVE-2026-47074 related
- https://github.com/ex-aws/ex_aws_sns/commit/1853d280b152d10384a1e21a22cf22152a60be48 patch