GHSA-5whh-4q9j-7v28

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Source
https://github.com/advisories/GHSA-5whh-4q9j-7v28
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-5whh-4q9j-7v28/GHSA-5whh-4q9j-7v28.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-5whh-4q9j-7v28
Published
2026-03-03T20:07:00Z
Modified
2026-03-04T15:11:32Z
Severity
  • 3.7 (Low) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
aws-kms-tls-auth vulnerable to memory overallocation
Details

Summary

aws-kms-tls-auth is an optional utility for s2n-tls that enables customers to use AWS KMS keys as part of the PSK extension field in a TLS 1.3 handshake. An issue exists in this library that can lead to overallocation of memory potentially resulting in a denial of service.

Impact

The PSK extension field in TLS 1.3 uses length-prefixed lists to encode variable-length data. aws-kms-tls-auth interprets the length prefix incorrectly resulting in additional memory allocation. 

s2n-tls limits ClientHello messages to 64 KB. Due to this issue, the server may allocate up to 10× the received size, meaning a single message could trigger an allocation of up to 640 KB. Repeated allocations of this size could exhaust server resources and lead to a denial-of-service.

No AWS services are affected. Applications should continue to follow best practices by limiting the number of in-flight handshakes and concurrent connections. Applications using the aws-kms-tls-auth crate should upgrade to version 0.0.3.

Impacted versions: < 0.0.3

Patches

This issue has been addressed in aws-kms-tls-auth v0.0.3 [1].

Workarounds

There is no workaround. Applications using aws-kms-tls-auth should upgrade to the most recent release.

Acknowledgement

s2n-tls would like to thank Joshua Rogers (https://joshua.hu/) of AISLE Research Team (https://aisle.com/) for collaborating on this issue through the coordinated disclosure process.

If there are any questions or comments about this advisory, contact AWS/Amazon Security via the vulnerability reporting page [2] or directly via email to aws-security@amazon.com. Please do not create a public GitHub issue.

[1] https://crates.io/crates/aws-kms-tls-auth/0.0.3 [2] Vulnerability reporting page: https://aws.amazon.com/security/vulnerability-reporting

Database specific 
{
    "cwe_ids":  [
        "CWE-119"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-03-03T20:07:00Z",
    "nvd_published_at":  null,
    "severity":  "LOW"
}
References

Affected packages

crates.io / aws-kms-tls-auth

Package

Name
aws-kms-tls-auth
View open source insights on deps.dev
Purl
pkg:cargo/aws-kms-tls-auth

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.0.3

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-5whh-4q9j-7v28/GHSA-5whh-4q9j-7v28.json"