{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-16318 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2026-16318 is a medium-severity denial of service vulnerability in Amazon s2n-tls, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-16318 and fix it if it is affected.\n\nWhat it is: CVE-2026-16318 is a medium-severity denial of service vulnerability in Amazon s2n-tls, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-16318 in the wild and no public exploit code.\n\nAffected product: Amazon s2n-tls. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-16318/ (Markdown: https://insights.sbomify.com/CVE-2026-16318/index.md)","id":"CVE-2026-16318","markdown":"https://insights.sbomify.com/CVE-2026-16318/index.md","name":"CVE-2026-16318","record":{"aliases":["GHSA-cr7x-863j-xrc7"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"TLS library","requires_auth":"none","summary":"An unauthenticated attacker can cause memory exhaustion in s2n-tls servers by forcing HelloRetryRequests, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"AMZN","cpe":[],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-401","name":"Missing Release of Memory after Effective Lifetime"}],"description":"The QUIC transport parameters extension handler in s2n-tls incorrectly uses s2n_alloc instead of s2n_realloc to store the peer's transport parameters. When a TLS 1.3 connection goes through a HelloRetryRequest, the handler is called twice on the same connection. On the second call, s2n_alloc zeroes the existing pointer before allocating new memory, causing the first allocation to be leaked.\n\nThis can occur during normal QUIC traffic when a client offers a key share group the server does not prefer. An unauthenticated user can amplify the issue by deliberately forcing HelloRetryRequests, causing up to approximately 64 KB of unreachable memory per handshake. Over time, this can lead to increased memory consumption on long-running server processes. The unreachable memory is only reclaimed when the process is restarted.\n\nOnly server-side QUIC-enabled deployments are affected. Non-QUIC TLS connections are not affected.\n\nWe recommend you upgrade s2n-tls to version v1.7.6","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"QUIC Transport Parameters Memory Leak During HelloRetryRequest in s2n-tls","id":"CVE-2026-16318","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Authentication Bypass via Execution After Redirect in FuyaSoft's Architect Panel Web Management Panel","id":"CVE-2026-16323"},"packages":[],"prev":{"headline":"Silent Drop of TLS 1.3 Encrypted Records in s2n-tls","id":"CVE-2026-16317"},"products":["s2n-tls"],"published":"2026-07-21","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-22","vendors":["Amazon"]},"summary":"An unauthenticated attacker can cause memory exhaustion in s2n-tls servers by forcing HelloRetryRequests, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2026-16318/"}