Vulnerability in Amazon (CVE-2026-16317)
Summary
Vulnerability in Amazon (CVE-2026-16317). Data can be tampered with by attackers.
Original description
The description as published by the source.
Bulletin ID: 2026-062-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 07/21/2026 13:15 PM PDT Description: s2n-tls is an open source C99 implementation of the TLS/SSL protocol. We have identified two distinct issues: - CVE-2026-16317: Silent Drop of TLS 1.3 Encrypted Records in s2n-tls Missing validation of the outer content_type byte on TLS 1.3 encrypted records in s2n-tls allows an active man-in-the-middle to silently drop individual application data records without either endpoint detecting the modification. RFC 8446 Section 5.2 requires that the outer content_type of all encrypted TLS 1.3 records must be application_data (0x17). The s2n-tls AEAD implementation hardcodes this value in the additional authenticated data rather than using the actual wire byte, so the outer content_type is not covered by the authentication tag. All TLS 1.3 connections are affected. Both TLS clients and servers are affected. TLS 1.2 and QUIC connections are not affected. - CVE-2026-16318: QUIC Transport Parameters Memory Leak During HelloRetryRequest in s2n-tls Incorrect use of s2n_alloc instead of s2n_realloc in the QUIC transport parameters extension handler in s2n-tls causes one memory allocation to be leaked each time a QUIC-enabled TLS 1.3 connection goes through a HelloRetryRequest. This can occur during normal handshakes when a client offers a key share group the server does not prefer, and can lead to increased memory consumption on long-running server proc…
Source: AWS Security Bulletins NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-16317 has been found in Amazon.
Data can be tampered with by attackers. CVSS score: 6.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Amazon CVE-2026-16317" on the vendor's site.
CVE-2026-16317 (Amazon) — CWE-354 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-354) exists in Amazon.
Check the vendor advisory for the affected versions of Amazon.
Severity: Medium (CVSS 6.5/10). Data can be tampered with by attackers.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Amazon' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'Amazon' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Amazonを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- AWS aws.amazon.com
- web aws.amazon.com
- web github.com
- web github.com