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No exploitation reportedFix available

CVE-2026-97032

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

No exploitation reported by the sources we read.

  • Published2026-10-08
  • Fixed in1.26.9
  • WeaknessCWE-362

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-10-0823:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-97032?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-97032?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV
golang
BranchAffectedFixed in
1.26< 1.26.91.26.9
golang.org/x/net
BranchAffectedFixed in
0.60< 0.60.00.60.0
stdlib
BranchAffectedFixed in
1.27≥ 1.27.0-0, < 1.27.21.27.2

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • CVE-2026-97032 Red Hat Product Security183 products fixed · 315 known affected

    net/http: net/http/internal/http2: golang: golang.org/x/net/http2: net/http: Denial of Service via concurrent HPACK encoder modification

    helm.src as a component of OpenShift Developer Tools and Services · openshift-pipelines-client.src as a component of OpenShift Pipelines · kn-workflow-plugin.src as a component of OpenShift Serverless · +312 more

  • RHSA-2026:87043 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: golang security, bug fix, and enhancement update

  • RHSA-2026:87042 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: golang security, bug fix, and enhancement update

  • RHSA-2026:87041 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: golang security, bug fix, and enhancement update

  • RHSA-2026:87040 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: golang security, bug fix, and enhancement update

  • RHSA-2026:86196 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: golang security, bug fix, and enhancement update

2 more advisories

Full record on NVD

Fix

  1. Update golang to 1.26.9
  2. Vendor fix Red Hat Product Security RHSA-2026:87043 · 21 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. Workaround from the vendor Red Hat Product Security RHSA-2026:87043 · 21 productsDisable HTTP/2 server processing in affected Go applications by setting the environment variable GODEBUG=http2server=0, or restrict network exposure to trusted clients. For applications managed by systemd, configure the environment variable by creating a service override: systemctl edit <service-…
  4. No fix planned, says the vendor Red Hat Product Security CVE-2026-97032 · 18 productsOut of support scope

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-10-08
Last Modified
2026-10-15
NVD status
Awaiting Analysis

Frequently asked questions

What is CVE-2026-97032?

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.

Is CVE-2026-97032 actively exploited?

Active exploitation of CVE-2026-97032 has not been confirmed. Its EPSS score was 0.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-97032?

CVE-2026-97032 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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