Skip to content
Fencer Vulns
medium 5.3

CVE-2026-40898 json

quic-go: HTTP/3 QPACK Trailer Expansion Memory Exhaustion

published 2026-06-03 5 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-34312 , GHSA-vvgj-x9jq-8cj9 , GO-2026-5676

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

quic-go is an implementation of the QUIC protocol in Go. Prior to version 0.59.1, an attacker can cause excessive memory allocation in quic-go's HTTP/3 client and server implementations by sending a QPACK-encoded HEADERS frame that decodes into a large trailer field section with many unique field names and/or large values. The implementation builds an `http.Header` for the corresponding `http.Request` or `http.Response`, while only enforcing limits on the size of the QPACK-compressed HEADERS frame, not on the decoded field section. This can lead to memory exhaustion. This is very similar to CVE-2025-64702. The difference is that this issue uses HTTP trailers, rather than HTTP headers, as the attack vector. A misbehaving or malicious peer can cause a denial-of-service (DoS) attack against quic-go's HTTP/3 servers or clients by triggering excessive memory allocation, potentially leading to crashes or resource exhaustion. This affects both servers and clients due to symmetric header construction. Version 0.59.1 enforces RFC 9114 decoded field section size limits for trailers as well. It incrementally decodes QPACK entries and checks the field section size after each entry, aborting the stream if an entry causes the limit to be exceeded.

Patch / fix

  • go github.com/quic-go/quic-go 0.59.1
  • quic-go_project quic-go 0.59.1
  • quic_project quic 0.59.1
  • receptor ansible automation platform inside 2.5, ansible automation platform developer 2.5, ansible automation platform 2.5 1.6.7-1.el8ap
  • receptor ansible automation platform inside 2.7, ansible automation platform inside 2.6, ansible automation platform inside 2.5 +5 more 1.6.7-1.el9ap
  • receptorctl ansible automation platform inside 2.5, ansible automation platform developer 2.5, ansible automation platform 2.5 1.6.7-1.el8ap
  • receptorctl ansible automation platform inside 2.6, ansible automation platform inside 2.5, ansible automation platform developer 2.6 +3 more 1.6.7-1.el9ap
  • python3.12-daphne ansible automation platform 2.5 4.2.2-1.el8ap
  • python3.12-daphne ansible automation platform 2.6, ansible automation platform 2.5 4.2.2-1.el9ap
  • python3.12-pillow ansible automation platform 2.5 12.3.0-1.el8ap
  • python3.12-pillow ansible automation platform 2.6, ansible automation platform 2.5 12.3.0-1.el9ap

red hat advisories RHSA-2026:50319RHSA-2026:50336RHSA-2026:50318RHSA-2026:40223RHSA-2026:15862

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40898 updated cvss 7.5

github.com/quic-go/quic-go: quic-go: Denial of Service via excessive memory allocation in HTTP/3 trailers

  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/lighthouse-coredns-rhel9 Red Hat Ansible Automation Platform 2 ansible-automation-platform-27/ee-supported-rhel9 Red Hat OpenShift Container Platform 4 openshift4/ose-coredns-rhel9
    affected: workaround, no fix available
  • Red Hat Ansible Automation Platform 2.5 for RHEL 8 receptor 1.6.7-1.el8ap Red Hat Ansible Automation Platform 2.5 for RHEL 9 receptor 1.6.7-1.el9ap
    fixed: vendor fix RHSA-2026:50319
  • Red Hat Ansible Automation Platform 2.6 ansible-automation-platform-26/receptor-rhel9 1785632117
    fixed: vendor fix RHSA-2026:50479
  • Red Hat Ansible Automation Platform 2.6 for RHEL 9 receptor 1.6.7-1.el9ap, receptorctl 1.6.7-1.el9ap Red Hat Ansible Automation Platform 2.6 for RHEL 10 receptor 1.6.7-1.el10ap, receptorctl 1.6.7-1.el10ap
    fixed: vendor fix RHSA-2026:50336
  • Red Hat Ansible Automation Platform 2.7 ansible-automation-platform-27/receptor-rhel9 1785389482
    fixed: vendor fix RHSA-2026:50340
  • Red Hat Ansible Automation Platform 2.7 for RHEL 9 receptor 1.6.7-1.el9ap Red Hat Ansible Automation Platform 2.7 for RHEL 10 receptor 1.6.7-1.el10ap
    fixed: vendor fix RHSA-2026:50318
  • Red Hat Container Native Virtualization 4.21 container-native-virtualization/kubevirt-apiserver-proxy-rhel9 1786125762
    fixed: vendor fix RHSA-2026:53734
  • Red Hat Hardened Images caddy 2.11.4-0.2.hum1, trivy 0.69.3-1.2.hum1
    fixed: vendor fix RHSA-2026:40223
show 8 more
  • Red Hat OpenShift Dev Spaces 3.30 devspaces/traefik-rhel9 1787756799
    fixed: vendor fix RHSA-2026:62260
  • Red Hat OpenShift Service Mesh 2 openshift-service-mesh/pilot-rhel8, openshift-service-mesh/proxyv2-rhel9, openshift-service-mesh/istio-cni-rhel8
    not affected: vulnerable code not present
  • Red Hat OpenShift Service Mesh 3 openshift-service-mesh/istio-cni-rhel9, openshift-service-mesh/istio-pilot-rhel9, openshift-service-mesh/istio-proxyv2-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/volsync-rhel9, rhacm2/lighthouse-agent-rhel9, rhacm2/volsync-operator-bundle, redhat-user-workloads/volsync-tenant/volsync-0-12, redhat-user-workloads/volsync-tenant/volsync-bundle-0-12, redhat-user-workloads/submariner-tenant/lighthouse-agent-0-20, +1 more Red Hat Ansible Automation Platform 2.5 for RHEL 8 receptorctl 1.6.7-1.el8ap, automation-hub 4.10.17-1.el8ap, python3.12-daphne 4.2.2-1.el8ap, python3.12-pyasn1 0.6.4-1.el8ap, python3.12-pillow 12.3.0-1.el8ap, python3.12-aiohttp 3.14.1-2.el8ap, +17 more Red Hat Ansible Automation Platform 2.5 for RHEL 9 receptorctl 1.6.7-1.el9ap, automation-hub 4.10.17-1.el9ap, python3.12-daphne 4.2.2-1.el9ap, python3.12-pyasn1 0.6.4-1.el9ap, python3.12-pillow 12.3.0-1.el9ap, python3.12-aiohttp 3.14.1-2.el9ap, +17 more Red Hat Ansible Automation Platform 2.6 ansible-automation-platform-26/hub-rhel9 1785753568, ansible-automation-platform-26/gateway-rhel9 1785780020, ansible-automation-platform-26/hub-web-rhel9 1785756951, ansible-automation-platform-26/mcp-tools-rhel9 1785633968, ansible-automation-platform-26/controller-rhel9 1785753810, ansible-automation-platform-26/de-minimal-rhel9 1785647559, +24 more Red Hat Ansible Automation Platform 2.6 for RHEL 9 automation-hub 4.11.12-1.el9ap, python3.12-daphne 4.2.2-1.el9ap, python3.12-pyasn1 0.6.4-1.el9ap, ansible-dev-tools 26.7.2-1.el9ap, python3.12-pillow 12.3.0-1.el9ap, aap-metrics-utility 0.7.6-3.el9ap, +33 more Red Hat Ansible Automation Platform 2.6 for RHEL 10 ansible-dev-tools 26.7.2-1.el10ap, python-tox-ansible 26.7.1-1.el10ap, python3-tox-ansible 26.7.1-1.el10ap, ansible-dev-tools+server 26.7.2-1.el10ap
    +3 more products
    Red Hat Ansible Automation Platform 2.7 ansible-automation-platform-27/hub-rhel9 1785376164, ansible-automation-platform-27/gateway-rhel9 1785435970, ansible-automation-platform-27/hub-web-rhel9 1785379466, ansible-automation-platform-27/mcp-tools-rhel9 1785374970, ansible-automation-platform-27/controller-rhel9 1785378052, ansible-automation-platform-27/de-minimal-rhel9 1785446384, +25 more Red Hat Ansible Automation Platform 2.7 for RHEL 9 receptorctl 1.6.7-1.el9ap, ansible-dev-tools 26.7.2-1.el9ap, python3.12-tox-ansible 26.7.1-1.el9ap, ansible-dev-tools+server 26.7.2-1.el9ap, automation-controller-cli 4.8.4-1.el9ap Red Hat Ansible Automation Platform 2.7 for RHEL 10 receptorctl 1.6.7-1.el10ap, ansible-dev-tools 26.7.2-1.el10ap, python-tox-ansible 26.7.1-1.el10ap, python3-tox-ansible 26.7.1-1.el10ap, ansible-dev-tools+server 26.7.2-1.el10ap, automation-controller-cli 4.8.4-1.el10ap
    not affected: vulnerable code not present
  • Red Hat Hardened Images rust Red Hat OpenShift Container Platform 4 redhat-user-workloads/ocp-art-tenant/art-images
    not affected: component not present
  • Red Hat OpenShift Container Platform 5 openshift5/ose-coredns-rhel9
    not affected: vulnerable code not present
  • Red Hat Openshift Data Foundation 4 odf4/odf-blackbox-exporter-rhel9
    not affected: component not present
  • Red Hat OpenShift Dev Spaces 3.30 devspaces/udi-rhel9 1787764814, devspaces/code-rhel9 1787762793, devspaces/server-rhel9 1787757597, devspaces/openvsx-rhel9 1787759145, devspaces/udi-base-rhel9 1787761882, devspaces/code-sshd-rhel9 1787762385, +10 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/quic-go/quic-go
<0.59.1
0.59.1

Affected products

  • quic-go quic-go

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.