CVE-2026-78663
The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
- CVSS 3.1
- 9.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - EPSS
- 0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-25)
- CWE
- CWE-675
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GO-2026-6612 | Go | stdlib | <1.26.9 | 1.26.9 |
| GO-2026-6612 | Go | stdlib | >=1.27.0-0 <1.27.2 | 1.27.2 |
| GO-2026-6612 | Go | golang.org/x/net | <0.60.0 | 0.60.0 |