{"id":"CVE-2026-10740","aliases":["EUVD-2026-36103","GHSA-9q54-f358-3fqf"],"status":"published","title":"Excessive memory allocation in s2n-quic","description":"Unbounded memory allocation in the CRYPTO frame reassembler in s2n-quic before 1.8.2 may allow an unauthenticated remote actor to cause a denial of service (degraded availability) by sending crafted QUIC Initial packets.\n\n\n\nTo remediate this issue, users should upgrade to v1.8.2.","severity":{"version":"4.0","score":6.9,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00291,"percentile":0.21918,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-770"],"published":"2026-06-10T18:09:36Z","modified":"2026-10-28T02:30:41Z","fixes":[{"ecosystem":"crates.io","package":"s2n-quic","fixed_in":["1.82.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"s2n-quic","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.81.0"},{"fixed":"1.82.0"}]}]},{"source":"osv","ecosystem":"crates.io","package":"s2n-quic","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.82.0"}]}]}],"products":[{"vendor":"aws","product":"s2n-quic"}],"references":[{"url":"https://github.com/aws/s2n-quic/releases/tag/v1.82.0","tags":["patch","fix","web"]},{"url":"https://aws.amazon.com/security/security-bulletins/2026-042-aws/","tags":["vendor-advisory","advisory"]},{"url":"https://github.com/aws/s2n-quic/security/advisories/GHSA-9q54-f358-3fqf","tags":["third-party-advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-10740","tags":["advisory"]},{"url":"https://aws.amazon.com/security/security-bulletins/2026-042-aws","tags":["web"]},{"url":"https://github.com/advisories/GHSA-9q54-f358-3fqf"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/10xxx/CVE-2026-10740.json","tags":["advisory"]},{"url":"https://github.com/aws/s2n-quic","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-10740","title":"Excessive memory allocation in s2n-quic","description":"Unbounded memory allocation in the CRYPTO frame reassembler in s2n-quic before 1.8.2 may allow an unauthenticated remote actor to cause a denial of service (degraded availability) by sending crafted QUIC Initial packets.\n\n\n\nTo remediate this issue, users should upgrade to v1.8.2.","status":"published","published":"2026-06-10T18:09:36.07Z","modified":"2026-06-10T19:14:59.133Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium","assessor":"cna"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T13:40:01.309549Z"}],"euvd":[{"id":"EUVD-2026-36103","description":"Unbounded memory allocation in the CRYPTO frame reassembler in s2n-quic before 1.8.2 may allow an unauthenticated remote actor to cause a denial of service (degraded availability) by sending crafted QUIC Initial packets.\n\n\n\nTo remediate this issue, users should upgrade to v1.8.2.","status":"published","published":"2026-06-10T18:09:36Z","modified":"2026-06-10T19:14:59Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium"}],"updated_at":"2026-11-02T18:20:44.937217Z"}],"ghsa":[{"id":"GHSA-9q54-f358-3fqf","title":"s2n-quic has excessive memory allocation","description":"s2n-quic is a Rust implementation of the QUIC protocol. An unauthenticated user can attempt to exhaust server memory on an s2n-quic endpoint by sending crafted CRYPTO frames with high offsets. The buffer used for processing CRYPTO frames does not enforce a maximum size. In the worst case, a single 1200-byte packet can cause approximately 9.4 MB of allocation. By repeatedly sending such packets, the resulting memory pressure could cause denial of service. No valid handshake is required.\n\nImpacted versions: \u003c= v1.81.0\n\n### Patches\nThis issue has been addressed in s2n-quic version v1.82.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. \n\n### Workarounds\nThere is no workaround that fully mitigates this issue. Upgrading to the patched version is the recommended remediation.\n\n### References\nIf there are any questions or comments about this advisory, contact AWS Security via the [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.","status":"published","published":"2026-08-14T21:44:19Z","modified":"2026-08-14T21:44:21Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:41:01.23108Z"}],"nvd":[{"id":"CVE-2026-10740","description":"Unbounded memory allocation in the CRYPTO frame reassembler in s2n-quic before 1.8.2 may allow an unauthenticated remote actor to cause a denial of service (degraded availability) by sending crafted QUIC Initial packets.\n\n\n\nTo remediate this issue, users should upgrade to v1.8.2.","status":"published","published":"2026-06-10T19:16:32.47Z","modified":"2026-10-26T11:10:00.157Z","cvss":[{"version":"4.0","score":6.9,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:23.485267Z"}],"osv":[{"id":"CVE-2026-10740","title":"Excessive memory allocation in s2n-quic","description":"Unbounded memory allocation in the CRYPTO frame reassembler in s2n-quic before 1.8.2 may allow an unauthenticated remote actor to cause a denial of service (degraded availability) by sending crafted QUIC Initial packets.\n\n\n\nTo remediate this issue, users should upgrade to v1.8.2.","status":"published","published":"2026-06-10T18:09:36.07Z","modified":"2026-10-28T02:30:41.618789781Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:44:54.933106Z"},{"id":"GHSA-9q54-f358-3fqf","title":"s2n-quic has excessive memory allocation","description":"s2n-quic is a Rust implementation of the QUIC protocol. An unauthenticated user can attempt to exhaust server memory on an s2n-quic endpoint by sending crafted CRYPTO frames with high offsets. The buffer used for processing CRYPTO frames does not enforce a maximum size. In the worst case, a single 1200-byte packet can cause approximately 9.4 MB of allocation. By repeatedly sending such packets, the resulting memory pressure could cause denial of service. No valid handshake is required.\n\nImpacted versions: \u003c= v1.81.0\n\n### Patches\nThis issue has been addressed in s2n-quic version v1.82.0. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. \n\n### Workarounds\nThere is no workaround that fully mitigates this issue. Upgrading to the patched version is the recommended remediation.\n\n### References\nIf there are any questions or comments about this advisory, contact AWS Security via the [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.","status":"published","published":"2026-08-14T21:44:19Z","modified":"2026-08-14T22:00:07.674402828Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"},{"version":"4.0","score":6.9,"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","level":"medium"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:46:44.225359Z"}]}}