How severe is GHSA-vw5v-4f2q-w9xf?

GHSA-vw5v-4f2q-w9xf has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-vw5v-4f2q-w9xf?

GHSA-vw5v-4f2q-w9xf affects the following packages: aws-lc-sys (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-vw5v-4f2q-w9xf?

Update aws-lc-sys to 0.38.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vw5v-4f2q-w9xf is resolved across your whole dependency graph.

How do I detect GHSA-vw5v-4f2q-w9xf in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aws-lc-sys, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-vw5v-4f2q-w9xf 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.

Is GHSA-vw5v-4f2q-w9xf actively exploited in the wild?

No public exploit code has been indexed for GHSA-vw5v-4f2q-w9xf 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 is the EPSS score for GHSA-vw5v-4f2q-w9xf?

GHSA-vw5v-4f2q-w9xf has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 55th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-vw5v-4f2q-w9xf?

GHSA-vw5v-4f2q-w9xf 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-vw5v-4f2q-w9xf published, and has it been updated?

GHSA-vw5v-4f2q-w9xf was published on March 3, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀

🦀 crates.io

Not in CISA KEV

HIGH severity

AWS-LC has PKCS7_verify Certificate Chain Validation BypassGHSA-vw5v-4f2q-w9xf

HIGH

GHSA-vw5v-4f2q-w9xf is a high-severity (CVSS 7.5) CWE-295 vulnerability in aws-lc-sys. A fix is available for aws-lc-sys — see the affected versions and patch details below.

Also known asCVE-2026-3336 GHSA-cfwj-9wp5-wqvpRUSTSEC-2026-0046

Published

Mar 3, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-vw5v-4f2q-w9xf.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs55th percentile — riskier than 55% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🦀aws-lc-sys

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

Description

Summary

AWS-LC is an open-source, general-purpose cryptographic library.

Impact

Improper certificate validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass certificate chain verification when processing PKCS7 objects with multiple signers, except the final signer.

Customers of AWS services do not need to take action. aws-lc-sys contains code from AWS-LC. Applications using aws-lc-sys should upgrade to the most recent release of aws-lc-sys.

Impacted versions:

aws-lc-sys versions: >= 0.24.0, < 0.38.0

Patches

The patch is included in v0.38.0

Workarounds

There is no workaround. Applications using aws-lc-sys should upgrade to the most recent release of aws-lc-sys.

Resources

If there are any questions or comments about this advisory, contact [AWS/Amazon] Security via the vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.

Acknowledgement

AWS-LC would like to thank Joshua Rogers (https://joshua.hu/) for collaborating on this issue through the coordinated vulnerability disclosure process.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`aws-lc-sys`	≥ 0.24.0&&< 0.38.0	0.38.0`cargo update -p aws-lc-sys --precise 0.38.0`

Affected Products

2 products · 2 configurations

Application

aws libcryptoamazon

≥ 1.41.0 && < 1.69.0

range

Application

aws-lc-sysamazon

≥ 0.24.0 && < 0.38.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aws-lc-sys, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update aws-lc-sys to 0.38.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vw5v-4f2q-w9xf 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.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for GHSA-vw5v-4f2q-w9xf (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat Trusted Artifact Signer 1.3	`rhtas/tuffer-rhel9:1773307309`	RHSA-2026:5459

Frequently Asked Questions

### Summary AWS-LC is an open-source, general-purpose cryptographic library. ### Impact Improper certificate validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass certificate chain verification when processing PKCS7 objects with multiple signers, except the final signer. Customers of AWS services do not need to take action. aws-lc-sys contains code from AWS-LC. Applications using aws-lc-sys should upgrade to the most recent release of aws-lc-sys. #### Impacted versions: aws-lc-sys versions: >= 0.24.0, < 0.38.0 ### Patches The patch is included in v0.38.0 ### Wor