Security readout for executives and security teams
Plain-English summary
AWS-LC applications may incorrectly trust a multi-signer PKCS7 object when a signer other than the last has an invalid certificate chain. An unauthenticated remote party could bypass an intended trust check and compromise data integrity. AWS states that customers of AWS services need no action; independently operated applications using AWS-LC should be assessed and upgraded.
Executive priority
Treat this as a high-priority integrity issue for independently operated applications using AWS-LC. Rapidly identify internet-facing or trust-sensitive PKCS7 processing, then upgrade to 1.69.0. Organizations using only AWS-managed services can document AWS’s no-action statement. There is no supplied evidence of active exploitation, so prioritization should be exposure-driven rather than emergency-wide.
Technical view
CVE-2026-3336 is a CWE-295 certificate-validation flaw in AWS-LC PKCS7_verify(). With multiple signers, chain verification can be bypassed for signers except the final signer. CVSS 4.0 is 8.7: network-reachable, low complexity, no privileges or interaction, with high integrity impact but no stated confidentiality or availability impact. AWS-LC 1.69.0 contains the fix.
Likely exposure
Exposure is most likely in applications that directly or indirectly use AWS-LC PKCS7_verify() to process untrusted, multi-signer PKCS7 objects. AWS-managed service customers are explicitly excluded from required action. The supplied affected-version metadata is insufficient to establish a complete vulnerable version range, so dependency and build-artifact verification is necessary.
Exploitation context
The issue is remotely reachable and requires neither authentication nor user interaction according to the CVSS vector. However, the supplied bundle marks it absent from KEV and provides no evidence of active exploitation or a public exploit. Practical impact depends on whether an application accepts multi-signer PKCS7 input and relies on every signer’s certificate chain being valid.
Researcher notes
The key condition is multiple signers: validation may be bypassed for every signer except the final one. The bundle identifies version 1.41.0 but also labels its default status unaffected, creating ambiguity; it does not establish a reliable affected range. Validate against AWS’s advisory and actual packaged binaries. Avoid equating the high CVSS score with confirmed exploitation.
Mitigation direction
- Upgrade applications using AWS-LC to version 1.69.0 or later.
- Inventory direct, transitive, statically linked, and vendored AWS-LC copies.
- Prioritize systems accepting untrusted multi-signer PKCS7 objects.
- Consult the AWS advisory for deployment-specific guidance and affected-version clarification.
- AWS service customers require no action according to AWS.
Validation and detection
- Confirm deployed binaries resolve to AWS-LC 1.69.0 or later.
- Identify application paths that call PKCS7_verify() or wrappers around it.
- Determine whether those paths process externally supplied multi-signer PKCS7 objects.
- Regression-test that an invalid chain for any signer causes verification failure.
- Review dependency manifests and compiled artifacts, not only source declarations.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-295: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-3336 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.7 (4.0)
- Known Exploited
- No
- Published
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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
3 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——AMZNCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6AMZNCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N3.93.6redhat-SADPVulnerability scoring details
Base CVSS 4.0 score
8.7HighVector: 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
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-03-02T22:01:15.917Z: Reported to Red Hat.
- 2026-03-02T21:15:16.709Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://aws.amazon.com/security/security-bulletins/2026-005-AWS/CVE reference, AMZN · vendor-advisory
- https://github.com/aws/aws-lc/releases/tag/v1.69.0CVE reference, AMZN · patch
- https://github.com/aws/aws-lc/security/advisories/GHSA-cfwj-9wp5-wqvpCVE reference, AMZN · third-party-advisory
- https://access.redhat.com/security/cve/CVE-2026-3336CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2444026CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3336.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:5459CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Certificate Validation
Improper Certificate Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.