s2n-quic has excessive memory allocation

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. Impacted versions: <= v1.81.0 ### Patches This 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.  ### Workarounds There is no workaround that fully mitigates this issue. Upgrading to the patched version is the recommended remediation. ### References If 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 [[email protected]](mailto:[email protected]). Please do not create a public GitHub issue.

Source published

14 Aug 2026 21:44:19 UTC

Source modified

14 Aug 2026 22:00:07 UTC

Observed here

24 Oct 2026 13:19:54 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS_V4 · 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

Publisher rating · MODERATE