CVE-2026-3337
Timing Side-Channel in AES-CCM Tag Verification in AWS-LC
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. `aws-lc-sys` contains code from AWS-LC. Applications using `aws-lc-sys` should upgrade to the most recent release of `aws-lc-sys`. ## Workarounds In the special cases of using AES-CCM with (M=4, L=2), (M=8, L=2), or (M=16, L=2), applications can workaround this issue by using AES-CCM through the EVP AEAD API using implementations `EVP_aead_aes_128_ccm_bluetooth`, `EVP_aead_aes_128_ccm_bluetooth_8`, and `EVP_aead_aes_128_ccm_matter` respectively. Otherwise, there is no workaround and applications using `aws-lc-sys` should upgrade to the most recent release.
How to fix CVE-2026-3337
To remediate CVE-2026-3337, upgrade the affected package to a fixed version below.
- —upgrade to 0.13.12 or later
- —upgrade to 0.13.12 or later
- —upgrade to 0.38.0 or later
- —upgrade to 0.38.0 or later
Is CVE-2026-3337 being exploited?
Low — EPSS is 1.1%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- >= 0.13.0, < 0.13.12
- >= 0.13.0, < 0.13.12
- >= 0.14.0, < 0.38.0
- >= 0.14.0, < 0.38.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N |