Aws Lc SysApplication · Amazon
CVE-2026-3336
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedImproper 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceAWS-LC's PKCS7_verify() function improperly validates certificate chains when processing PKCS7 objects containing multiple signers. The vulnerability causes the verification logic to skip chain validation for all signers except the final one, potentially allowing an unauthenticated attacker to inject malicious certificates into the chain.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Aws Lc SysApplication
>= 0.24.0, < 0.38.0>= 1.41.0, < 1.69.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify AWS-LC library versionLocate the installed AWS-LC library (commonly named libaws-lc-sys.so, libaws-lc.so, or libaws-crypto-utils.so on Linux; or check via package manager: apt list --installed | grep aws-lc, yum list installed | grep aws-lc, or cargo tree -p aws-lc-sys for Rust projects). Inspect the library file or query its version information.Affected if The installed version falls within >= 0.24.0 and < 0.38.0 for aws-lc-sys, or >= 1.41.0 and < 1.69.0 for aws-libcrypto.
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Identify PKCS7 verification usage in applicationSearch application source code for calls to PKCS7_verify(), PKCS7_get0_signers(), or similar PKCS7 verification functions. Check for linking against aws-lc-sys or aws-crypto-utils libraries using ldd on Linux executables or dependency analysis tools.Affected if The application links against an affected AWS-LC version and calls PKCS7 verification functions.
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Check for PKCS7 multi-signer processingAudit application code or runtime behavior to determine if PKCS7 objects with multiple signers are processed. Review PKCS7 input sources such as signed documents, S/MIME messages, or code signing packages that may contain more than one signer certificate.Affected if The application processes PKCS7 objects where the content has multiple signers and verification relies on the affected AWS-LC PKCS7_verify() function.
The environment is affected if it uses AWS-LC version 0.24.0 to < 0.38.0 (aws-lc-sys) or 1.41.0 to < 1.69.0 (aws-libcrypto) and performs PKCS7 verification on objects with multiple signers.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped0.38.01.69.0
Upgrade AWS-LC to version 1.69.0 or later to obtain the patched library with proper multi-signer certificate chain validation.
1.69.0
- 1. Identify all applications and services that depend on the AWS-LC library (aws-lc-sys or aws-libcrypto)
- 2. Update the dependency version to 1.69.0 or later for aws-libcrypto (or 0.38.0+ for aws-lc-sys)
- 3. Rebuild and recompile all affected applications
- 4. Test that PKCS7 certificate verification functions correctly after the upgrade
- 5. Deploy the updated applications to production environments
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Aws Lc Sys
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-3336 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-3336 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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