--- id: CVE-2026-97031 title: >- Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references summary: >- Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references. We now reject t… 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-405 - CWE-770 vendor: stdlib product: stdlib affected: - 'stdlib >= 1.27.0-0, < 1.27.2' patched: - stdlib 1.27.2 published: '2026-10-08' updated: '2026-10-09' sourceUpdated: '2026-10-09T16:35:35.900' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97031' references: - url: 'https://go.dev/cl/847312' label: security@golang.org - url: 'https://go.dev/issue/81855' label: security@golang.org - url: 'https://groups.google.com/g/golang-announce/c/U2fTuyDJznI' label: security@golang.org - url: 'https://pkg.go.dev/vuln/GO-2026-6607' label: security@golang.org - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97031.json - url: 'https://access.redhat.com/security/cve/CVE-2026-97031' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2548336' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97031' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97031' - 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-2026:86196' - url: 'https://access.redhat.com/errata/RHSA-2026:87040' - url: 'https://access.redhat.com/errata/RHSA-2026:88316' - url: 'https://access.redhat.com/errata/RHSA-2026:88280' - url: 'https://access.redhat.com/errata/RHSA-2026:88188' - url: 'https://access.redhat.com/errata/RHSA-2026:88189' - 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-2026:88354' - url: 'https://access.redhat.com/errata/RHSA-2026:87245' - url: 'https://access.redhat.com/errata/RHSA-2026:89884' - url: 'https://access.redhat.com/errata/RHSA-2026:88397' - url: 'https://access.redhat.com/errata/RHSA-2026:89892' - url: 'https://access.redhat.com/errata/RHSA-2026:89751' - url: 'https://access.redhat.com/errata/RHSA-2026:89832' - url: 'https://access.redhat.com/errata/RHSA-2026:89741' - url: 'https://access.redhat.com/errata/RHSA-2026:89888' - url: 'https://access.redhat.com/errata/RHSA-2026:89908' tags: - nvd - osv - go - csaf - vex - red-hat - cve.org aliases: - GO-2026-6607 - BIT-golang-2026-97031 ecosystem: go ingestedAt: '2026-10-09T00:19:50.981Z' epss: 0.00519 epssPercentile: 0.43882 ssvc: exploitation: none automatable: 'yes' technicalImpact: partial timestamp: '2026-10-09T15:59:09.530145Z' --- ## Overview Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references. We now reject these as malformed and curb the memory amplification vector as a result. ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Package advisory (CVE-2026-97031) Affected packages: - `stdlib >= 1.27.0-0, < 1.27.2` Patched in: - `stdlib 1.27.2` Source: https://osv.dev/vulnerability/GO-2026-6607 ## Vendor advisories - **Red Hat VEX** · Important · 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, OpenShift Pipelines, OpenShift Serverless, OpenShift Service Mesh 3, … · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97031.json) - **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-2026:86196** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86196) - **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-2026:88316** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88316) - **RHSA-2026:88280** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88280) - **RHSA-2026:88188** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88188) - **RHSA-2026:88189** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88189) - **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-2026:87245** · 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) - **RHSA-2026:89884** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-10-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:89884) - **RHSA-2026:88397** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-10-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:88397) - **RHSA-2026:89892** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-10-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:89892) - **RHSA-2026:89751** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:89751) - **RHSA-2026:89832** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-10-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:89832)