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8.2
AWS-LC Library Leaks Information Through Encryption Speed
GHSA-65p9-r9h6-22vj
Summary
The AWS-LC library, used by AWS services and some customer applications, has a flaw that allows an attacker to figure out whether a encrypted message is valid by measuring how long the encryption takes. This is a security risk for applications that use aes-ccm encryption, and customers should upgrade to the latest version of the library to fix the issue.
What to do
- Update aws-lc-sys to version 0.38.0.
- Update aws-lc-fips-sys to version 0.13.12.
Affected software
| Vendor | Product | Affected versions | Fix available |
|---|---|---|---|
| – | aws-lc-sys | > 0.14.0 , <= 0.38.0 | 0.38.0 |
| – | aws-lc-fips-sys | > 0.13.0 , <= 0.13.12 | 0.13.12 |
Original title
AWS-LC has Timing Side-Channel in AES-CCM Tag Verification
Original description
### Summary
AWS-LC is an open-source, general-purpose cryptographic library.
### Impact
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 and aws-lc-fips-sys contain code from AWS-LC. Applications using aws-lc-sys or aws-lc-fips-sys should upgrade to the most recent releases of aws-lc-sys or aws-lc-fips-sys.
### Impacted versions:
- aws-lc-sys versions: >= 0.14.0, < 0.38.0
- aws-lc-fips-sys versions: >= v0.13.0, < 0.13.12.
### Patches
The patch is included in aws-lc-sys v.0.38.0 and aws-lc-fips-sys v0.13.12.
### 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 or aws-lc-fips-sys should upgrade to the most recent releases of aws-lc-sys or aws-lc-fips-sys.
### Resources
If there are any questions or comments about this advisory, contact [AWS/Amazon] Security via the[vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [[email protected]](mailto:[email protected]). Please do not create a public GitHub issue.
### Acknowledgement
AWS-LC would like to thank Joshua Rogers (https://joshua.hu/) for collaborating on this issue through the coordinated vulnerability disclosure process.
AWS-LC is an open-source, general-purpose cryptographic library.
### Impact
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 and aws-lc-fips-sys contain code from AWS-LC. Applications using aws-lc-sys or aws-lc-fips-sys should upgrade to the most recent releases of aws-lc-sys or aws-lc-fips-sys.
### Impacted versions:
- aws-lc-sys versions: >= 0.14.0, < 0.38.0
- aws-lc-fips-sys versions: >= v0.13.0, < 0.13.12.
### Patches
The patch is included in aws-lc-sys v.0.38.0 and aws-lc-fips-sys v0.13.12.
### 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 or aws-lc-fips-sys should upgrade to the most recent releases of aws-lc-sys or aws-lc-fips-sys.
### Resources
If there are any questions or comments about this advisory, contact [AWS/Amazon] Security via the[vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [[email protected]](mailto:[email protected]). Please do not create a public GitHub issue.
### Acknowledgement
AWS-LC would like to thank Joshua Rogers (https://joshua.hu/) for collaborating on this issue through the coordinated vulnerability disclosure process.
ghsa CVSS3.1
5.9
ghsa CVSS4.0
8.2
Vulnerability type
CWE-208
- https://github.com/aws/aws-lc-rs/security/advisories/GHSA-65p9-r9h6-22vj
- https://github.com/aws/aws-lc/security/advisories/GHSA-frmv-5gcm-jwxh
- https://nvd.nist.gov/vuln/detail/CVE-2026-3337
- https://aws.amazon.com/security/security-bulletins/2026-005-AWS
- https://github.com/advisories/GHSA-65p9-r9h6-22vj
Published: 3 Mar 2026 · Updated: 7 Mar 2026 · First seen: 6 Mar 2026