How severe is CVE-2026-3338?

CVE-2026-3338 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-3338 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3338?

CVE-2026-3338 primarily affects Amazon Aws-lc-sys. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-3338?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-3338 have an EU (EUVD) identifier?

Yes. CVE-2026-3338 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9266.

When was CVE-2026-3338 published?

CVE-2026-3338 was published on 2026-03-02 and last updated on 2026-06-30.

CVE-2026-3338

CVE-2026-3338 is a high-severity vulnerability in Amazon Aws-lc-sys with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-9266
Weakness: CWE-347
Affected product: Amazon Aws-lc-sys
Published: 2026-03-02
Last modified: 2026-06-30

Description

Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes. Customers of AWS services do not need to take action. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.

Frequently asked questions

What is CVE-2026-3338?: Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature verification when processing PKCS7 objects with Authenticated Attributes. Customers of AWS services do not need to take action. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.
How severe is CVE-2026-3338?: CVE-2026-3338 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-3338 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3338?: CVE-2026-3338 primarily affects Amazon Aws-lc-sys. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-3338?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-3338 have an EU (EUVD) identifier?: Yes. CVE-2026-3338 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9266.
When was CVE-2026-3338 published?: CVE-2026-3338 was published on 2026-03-02 and last updated on 2026-06-30.

References

Affected products (2)

cpe:2.3:a:amazon:aws-lc-sys:*:*:*:*:*:rust:*:*
cpe:2.3:a:amazon:aws_libcrypto:*:*:*:*:*:*:*:*

More vulnerabilities in Amazon Aws-lc-sys

CVE-2026-3336 — High (CVSS 7.5): Improper certificate validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass certificate chain…
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