CVE-2026-78669

HIGH7.5

Excessive CPU consumption from repeated initial window changes in net/http

Published Oct 8, 2026

Modified 2 weeks ago

Details

A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.

References

WEB

https://go.dev/cl/847186

WEB

https://go.dev/cl/847308

WEB

https://go.dev/issue/81742

WEB

https://groups.google.com/g/golang-announce/c/U2fTuyDJznI

WEB

https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs

WEB

https://pkg.go.dev/vuln/GO-2026-6611

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-78669

CVSS Analysis

CVSS v3.1

7.5

Exploitability

Attack Vector

NetworkAV:N

Attack Complexity

LowAC:L

Privileges Required

NonePR:N

User Interaction

NoneUI:N

Scope

UnchangedS:U

Impact

Confidentiality

NoneC:N

Integrity

NoneI:N

Availability

HighA:H

7.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Ecosystems

Timeline

PublishedOct 8, 2026

ModifiedOct 9, 2026