CVE-2026-3336
CVE-2026-3336 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-295.
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-2026-9264
- Weakness: CWE-295
- Affected product: Amazon Aws-lc-sys
- Published:
- Last modified:
Description
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. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.
Frequently asked questions
- What is CVE-2026-3336?
- 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. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.
- How severe is CVE-2026-3336?
- CVE-2026-3336 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-2026-3336 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-2026-3336?
- CVE-2026-3336 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-2026-3336?
- 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-2026-3336 have an EU (EUVD) identifier?
- Yes. CVE-2026-3336 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-9264.
- When was CVE-2026-3336 published?
- CVE-2026-3336 was published on 2026-03-02 and last updated on 2026-06-30.
References
- https://aws.amazon.com/security/security-bulletins/2026-005-AWS/
- https://github.com/aws/aws-lc/releases/tag/v1.69.0
- https://github.com/aws/aws-lc/security/advisories/GHSA-cfwj-9wp5-wqvp
- https://access.redhat.com/errata/RHSA-2026:5459
- https://access.redhat.com/security/cve/CVE-2026-3336
- https://bugzilla.redhat.com/show_bug.cgi?id=2444026
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3336.json
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-2026-3338 — High (CVSS 7.5): Improper signature validation in PKCS7_verify() in AWS-LC allows an unauthenticated user to bypass signature…
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