How severe is GHSA-8jgf-23q5-x7xx?

No CVSS score has been assigned to GHSA-8jgf-23q5-x7xx yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-8jgf-23q5-x7xx?

GHSA-8jgf-23q5-x7xx affects the following packages: ex_aws_sns (Hex). Ecosystems affected: Hex.

How do I fix GHSA-8jgf-23q5-x7xx?

Update ex_aws_sns to 2.3.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8jgf-23q5-x7xx is resolved across your whole dependency graph.

How do I detect GHSA-8jgf-23q5-x7xx in my Hex dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ex_aws_sns. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-8jgf-23q5-x7xx if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-8jgf-23q5-x7xx?

O3 pinpoints whether GHSA-8jgf-23q5-x7xx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-8jgf-23q5-x7xx actively exploited in the wild?

No public exploit code has been indexed for GHSA-8jgf-23q5-x7xx yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is GHSA-8jgf-23q5-x7xx?

GHSA-8jgf-23q5-x7xx is classified as CWE-295 (CWE-295). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-8jgf-23q5-x7xx published, and has it been updated?

GHSA-8jgf-23q5-x7xx was published on June 26, 2026 and was last updated on June 30, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💧 Hex

GHSA-8jgf-23q5-x7xx

ex_aws_sns: Trusted-attacker `SigningCertURL` permits complete SNS signature bypass

Also known asCVE-2026-47074EEF-CVE-2026-47074

Published

Jun 26, 2026

Updated

Jun 30, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

💧ex_aws_sns

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.

Description

Summary

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 its host is an AWS-owned SNS certificate domain. An unauthenticated attacker who can POST to any endpoint that calls verify_message/1 can supply an attacker-controlled SigningCertURL, sign a forged SNS message with their own RSA key, and cause the function to return :ok, completely bypassing SNS signature verification.

Details

In lib/ex_aws/sns.ex (lines 475–483), verify_message/1 performs three checks: validate_message_params/1 (confirms required fields are present), validate_signature_version/1 (confirms SignatureVersion == "1"), then signature verification. The signature step calls ExAws.SNS.PublicKeyCache.get(message["SigningCertURL"]) and passes the result to :public_key.verify/4.

Neither validate_message_params/1 nor any other step checks that SigningCertURL is an HTTPS URL or that the hostname matches the expected pattern (e.g. sns.<region>.amazonaws.com). PublicKeyCache.get/1 in lib/ex_aws/sns/public_key_cache.ex fetches whatever URL is provided and caches the certificate. The RSA signature then verifies against the attacker's own public key, and verify_message/1 returns :ok.

PoC

Generate an RSA keypair and host the DER/PEM public certificate at any URL reachable from the target server (e.g. http://attacker.example/cert.pem).
Build a forged Notification payload with an arbitrary TopicArn and Message, compute the canonical string-to-sign per the SNS spec, and sign it with the attacker private key.
Set SigningCertURL to the attacker URL and Signature to the base64-encoded signature.
POST the forged payload to any SNS webhook endpoint that calls ExAws.SNS.verify_message/1.
The function returns :ok; the application treats the message as authentic.

Configurations

The application must expose an HTTP endpoint that calls ExAws.SNS.verify_message/1 on incoming request bodies (the standard SNS webhook pattern).

Impact

Complete SNS signature authentication bypass. Affects ex_aws_sns from 2.0.1 through 2.3.4. Consequences include spoofing arbitrary Notification payloads, auto-confirming attacker-controlled SubscribeURL values to hijack topic delivery, and spoofing UnsubscribeConfirmation to disrupt legitimate subscriptions. No authentication or special configuration on the attacker side is required. CVSS v4.0: 8.7 (HIGH).

Resources

Introduction commit: https://github.com/ex-aws/ex_aws_sns/commit/a7ec21880943f4dac1d59bda557db0ffcd2b61fa
Patch commit: https://github.com/ex-aws/ex_aws_sns/commit/1853d280b152d10384a1e21a22cf22152a60be48

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`ex_aws_sns`	≥ 2.0.1&&< 2.3.5	2.3.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ex_aws_sns. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update ex_aws_sns to 2.3.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8jgf-23q5-x7xx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-8jgf-23q5-x7xx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-8jgf-23q5-x7xx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Summary `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 its host is an AWS-owned SNS certificate domain. An unauthenticated attacker who can POST to any endpoint that calls `verify_message/1` can supply an attacker-controlled `SigningCertURL`, sign a forged SNS message with their own RSA key, and cause the function to return `:ok`, completely bypassing SNS signature verification. ### Details In `lib/ex_aws/sns.ex` (lines 475–483), `verify_message/1` performs three

O3 Security · Impact-Aware SCA

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