CVE-2026-97031
Public on 2026-10-08
Modified on 2026-10-10
Description
Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references.
We now reject these as malformed and curb the memory amplification vector as a result.
NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81855
NOTE: Fixed by: https://github.com/golang/go/commit/f022e61963529d5e691f0e42a87fd5b520f01636 (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/eb1bf6e0c4f68b23409483b156e1455696508c6e (go1.26.9)
We now reject these as malformed and curb the memory amplification vector as a result.
NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9
NOTE: https://github.com/golang/go/issues/81855
NOTE: Fixed by: https://github.com/golang/go/commit/f022e61963529d5e691f0e42a87fd5b520f01636 (go1.27.2)
NOTE: Fixed by: https://github.com/golang/go/commit/eb1bf6e0c4f68b23409483b156e1455696508c6e (go1.26.9)
CVSS v3 Base Score
See breakdown
Affected Packages
| Platform | Package | Release Date | Advisory | Status |
|---|---|---|---|---|
| Amazon Linux 2 - Core | golang | Pending Fix | ||
| Amazon Linux 2 - Golang1.11 Extra | golang | No Fix Planned | ||
| Amazon Linux 2 - Golang1.19 Extra | golang | No Fix Planned | ||
| Amazon Linux 2 - Golang1.9 Extra | golang | No Fix Planned | ||
| Amazon Linux 2023 | golang | Pending Fix | ||
| Amazon Linux 2027 Preview | golang | Pending Fix |
CVSS Scores
| Score Type | Score | Vector | |
|---|---|---|---|
| Amazon Linux | CVSSv3 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |