CVE-2026-10740 Excessive memory allocation in s2n-quic
Unauthenticated remote attackers can cause denial of service via excessive memory allocation in the s2n-quic library by sending crafted QUIC Initial packets.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-10740?
CVE-2026-10740 is a medium-severity denial of service vulnerability in AWS s2n-quic, published on 10 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
To remediate this issue, users should upgrade to v1.8.2.
Weakness: CWE-770
Which versions are affected by CVE-2026-10740?
2 open source packages ship an affected version, including s2n-quic.
| Package | Affected | Fixed in |
|---|---|---|
s2n-quic crates.io | All versions | 1.82.0 |
s2n-quic crates.io | All versions | 1.82.0 |
How do I fix CVE-2026-10740?
Upgrade s2n-quic to 1.82.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-10740 being exploited?
There is no known exploitation of CVE-2026-10740 in the wild and no public exploit code.
Sources
Also known as GHSA-9q54-f358-3fqf.