Medium severity · published Jun 10, 2026
CVE-2026-10740
Excessive memory allocation in s2n-quic
5.3
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
S2
s2n-quic · AWS
through 1.8.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-10740
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-10740
aws.amazon.com
https://aws.amazon.com/security/security-bulletins/2026-042-aws/
github.com
https://github.com/aws/s2n-quic/releases/tag/v1.82.0
github.com
https://github.com/aws/s2n-quic/security/advisories/GHSA-9q54-f358-3fqf
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