CVE-2026-97032
HTTP/2 server crash due to HPACK encoder race in net/http
- Published
- Updated
- Reserved
- Assigned by
- Go
Description
HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently. This happens because the server modifies the HPACK encoder from two goroutines without synchronization: one uses the encoder to encode a HEADERS frame as part of a response sent to a client and the other modifies the encoder's table size when handling a SETTINGS frame containing SETTINGS_HEADER_TABLE_SIZE that a client sends. A malicious client can repeatedly send a request while changing the header table size to crash the server.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.49% · top 58% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Weakness
- CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (opens in a new tab)All about CWE-362 and its CVEs
Affected products
Go standard library · net/http
- affected < 1.26.9
Go standard library · net/http/internal/http2
- affected 1.27.0-0 – < 1.27.2
golang.org/x/net · golang.org/x/net/http2
- affected < 0.60.0
References (6)
- https://go.dev/cl/847188 (opens in a new tab)
- https://go.dev/cl/847313 (opens in a new tab)
- https://go.dev/issue/81867 (opens in a new tab)
- https://groups.google.com/g/golang-announce/c/U2fTuyDJznI (opens in a new tab)
- https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs (opens in a new tab)
- https://pkg.go.dev/vuln/GO-2026-6617 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-97032)Record last updated .