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Full vulnerability report · 2026
CVE-2026-3338High confidence

PKCS7_verify Signature Validation Bypass in AWS-LC

AWS · AWS-LC

8.7HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-3338 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityaws-lc: AWS-LC: Signature bypass due to improper validation in PKCS7_verify()
7 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • openshift-sandboxed-containers/osc-podvm-payload-rhel9 as a component of Confidential Compute Attestation
  • clevis-pin-trustee.src as a component of Red Hat Enterprise Linux 10
  • trustee-kbs as a component of Red Hat Enterprise Linux 10
  • clevis-pin-trustee.src as a component of Red Hat Enterprise Linux 9
  • kata-containers as a component of Red Hat OpenShift Container Platform 4
  • kata-containers.src as a component of Red Hat OpenShift Container Platform 4
  • rhtpa/rhtpa-trustification-service-rhel9 as a component of Red Hat Trusted Profile Analyzer
Summary
A flaw was found in AWS-LC. An unauthenticated user can bypass signature verification when processing PKCS7 objects with Authenticated Attributes due to improper signature validation in the PKCS7_verify() function. This vulnerability allows an attacker to potentially compromise the integrity of signed data.
Remediation
Red Hat Trusted Artifact Signer simplifies cryptographic signing and verifying of software artifacts such as container images, binaries and source code changes. It is a self-managed on-premise deployment of the Sigstore project available at https://sigstore.dev Platform Engineers, Software Developers and Security Professionals may use RHTAS to ensure the integrity, transparency and assurance of their organization's software supply chain. For details on using the operator, refer to the product documentation at https://access.redhat.com/documentation/en-us/red_hat_trusted_artifact_signer/1.3 You can find the release notes for this version of Red Hat Trusted Artifact Signer at https://access.redhat.com/documentation/en-us/red_hat_trusted_artifact_signer/1.3/html-single/release_notes/index
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-9266

No EUVD known-exploited evidence

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.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
8.7 · CVSS 4.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

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.

What

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.

Why

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Verification of Cryptographic Signature → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-347 ↗

CWE-347: Improper Verification of Cryptographic Signature. The product does not verify, or incorrectly verifies, the cryptographic signature for data.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
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

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCNoneVulnerable-system confidentiality: No direct loss is represented by this metric.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-347
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-9266Official EUVD mapping

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.

Official EUVD record
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
openshift-sandboxed-containers/osc-podvm-payload-rhel9 as a component of Confidential Compute Attestation; clevis-pin-trustee.src as a component of Red Hat Enterprise Linux 10; trustee-kbs as a component of Red Hat Enterprise Linux 10; clevis-pin-trustee.src as a component of Red Hat Enterprise Linux 9; kata-containers as a component of Red Hat OpenShift Container Platform 4; kata-containers.src as a component of Red Hat OpenShift Container Platform 4; rhtpa/rhtpa-trustification-service-rhel9 as a component of Red Hat Trusted Profile Analyzer
Fixed
registry.redhat.io/rhtas/tuffer-rhel9@sha256:f30c3610c1c840ea8edb99c2679edb09768c45012979da1389605c6a54204292_amd64 as a component of Red Hat Trusted Artifact Signer 1.3; registry.redhat.io/rhtas/tuftool-rhel9@sha256:cc2676a9d70599503faf8ca413e7bbc29cd523782a3d1e81bfc8f9e6323b4a28_amd64 as a component of Red Hat Trusted Artifact Signer 1.3
Action
Red Hat Trusted Artifact Signer simplifies cryptographic signing and verifying of software artifacts such as container images, binaries and source code changes. It is a self-managed on-premise deployment of the Sigstore project available at https://sigstore.dev Platform Engineers, Software Developers and Security Professionals may use RHTAS to ensure the integrity, transparency and assurance of their organization's software supply chain. For details on using the operator, refer to the product documentation at https://access.redhat.com/documentation/en-us/red_hat_trusted_artifact_signer/1.3 You can find the release notes for this version of Red Hat Trusted Artifact Signer at https://access.redhat.com/documentation/en-us/red_hat_trusted_artifact_signer/1.3/html-single/release_notes/index
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 2 Mar 2026 · Last source change 21 Aug 2026, 12:12 UTC · CWE-347 · Improper Verification of Cryptographic Signature

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-9266
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-9266↗Vendor CSAF · Red Hat Product Security↗CVE authority or vendor reference↗Vendor advisory↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-3338 · cve.blacktree.nl