CVE-2026-97032

HTTP/2 server crash due to HPACK encoder race in net/http

Published Oct 8, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-362
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
First Time appeared Go Standard Library
Go Standard Library net/http
Go Standard Library net/http2
Vendors & Products Go Standard Library
Go Standard Library net/http
Go Standard Library net/http2
Type Values Removed Values Added
Weaknesses CWE-362
Type Values Removed Values Added
Weaknesses CWE-362
Type Values Removed Values Added
Weaknesses CWE-366
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
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.
Title HTTP/2 server crash due to HPACK encoder race in net/http
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Go
Published
Updated
Oct 15, 2026, 3:46 PM
Reserved
Sep 23, 2026, 11:03 PM
Status
Awaiting Analysis
Published
Oct 8, 2026, 11:17 PM
Modified
Oct 15, 2026, 4:18 PM
Severity
Moderate
Public date
Oct 8, 2026, 10:54 PM