--- id: CVE-2026-97032 title: >- HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently summary: >- 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 … severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-362 - CWE-366 vendor: stdlib product: stdlib affected: - stdlib < 1.26.9 - 'stdlib >= 1.27.0-0, < 1.27.2' - golang.org/x/net < 0.60.0 patched: - stdlib 1.26.9 - stdlib 1.27.2 - golang.org/x/net 0.60.0 published: '2026-10-08' updated: '2026-10-15' sourceUpdated: '2026-10-15T16:18:24.967' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97032' references: - url: 'https://go.dev/cl/847188' label: security@golang.org - url: 'https://go.dev/cl/847313' label: security@golang.org - url: 'https://go.dev/issue/81867' label: security@golang.org - url: 'https://groups.google.com/g/golang-announce/c/U2fTuyDJznI' label: security@golang.org - url: 'https://groups.google.com/g/golang-announce/c/ZPwCyRUuGBs' label: security@golang.org - url: 'https://pkg.go.dev/vuln/GO-2026-6617' label: security@golang.org - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97032.json - url: 'https://access.redhat.com/security/cve/CVE-2026-97032' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2548337' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97032' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97032' - url: 'https://access.redhat.com/errata/RHSA-2026:87040' - url: 'https://access.redhat.com/errata/RHSA-2026:86093' - url: 'https://access.redhat.com/errata/RHSA-2026:86203' - url: 'https://access.redhat.com/errata/RHSA-2026:87246' - url: 'https://access.redhat.com/errata/RHSA-2026:87041' - url: 'https://access.redhat.com/errata/RHSA-2026:87042' - url: 'https://access.redhat.com/errata/RHSA-2026:87043' - url: 'https://access.redhat.com/errata/RHSA-2026:86196' - url: 'https://access.redhat.com/errata/RHSA-2026:87245' tags: - nvd - osv - go - cve.org - csaf - vex - red-hat epss: 0.0049 epssPercentile: 0.41939 aliases: - GO-2026-6617 - BIT-golang-2026-97032 ecosystem: go ssvc: exploitation: none automatable: 'yes' technicalImpact: partial timestamp: '2026-10-15T15:46:16.190858Z' ingestedAt: '2026-10-09T00:19:50.981Z' scores: nvd: 7.5 vendor: 5.9 --- ## Overview 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 Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Package advisory (CVE-2026-97032) Affected packages: - `stdlib < 1.26.9` - `stdlib >= 1.27.0-0, < 1.27.2` - `golang.org/x/net < 0.60.0` Patched in: - `stdlib 1.26.9` - `stdlib 1.27.2` - `golang.org/x/net 0.60.0` Source: https://osv.dev/vulnerability/GO-2026-6617 ## Vendor advisories - **RHSA-2026:87040** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87040) - **RHSA-2026:86093** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86093) - **RHSA-2026:86203** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86203) - **RHSA-2026:87246** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87246) - **RHSA-2026:87041** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87041) - **RHSA-2026:87042** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87042) - **RHSA-2026:87043** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87043) - **RHSA-2026:86196** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86196) - **Red Hat VEX** · Moderate · affected: OpenShift Developer Tools and Services, OpenShift Pipelines, OpenShift Serverless, OpenShift Service Mesh 3, Red Hat Ansible Automation Platform 2, Red Hat Ceph Storage 7, … · no fix planned: OpenShift Developer Tools and Services, Red Hat Ansible Automation Platform 2, Red Hat OpenStack Platform 16.2, Red Hat OpenStack Platform 17.1, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97032.json) - **RHSA-2026:87245** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-10-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:87245)