Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Unrated

Excessive CPU consumption from repeated initial window changes in net/http

CVE-2026-78669

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (golang.org/x/net 0.60.0; stdlib 1.27.2, 1.26.9), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • Go golang.org/x/net

    Affected
    < 0.60.0
    Fixed in
    0.60.0

  • Go stdlib

    Affected
    < 1.26.9>= 1.27.0-0, < 1.27.2
    Fixed in
    1.26.9, 1.27.2

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
not scored
EPSS
  • CVE-2026-78669: 0.61% estimated exploitation activity in the next 30 days; percentile 49.47 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from osv record GO-2026-6611

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-78669

Advisory: Excessive CPU consumption from repeated initial window changes in net/http
IDs: CVE-2026-78669
Record: https://patchnext.com/advisories/cve-2026-78669 (revision 1, source checked 23 Oct 2026, 22:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: golang.org/x/net 0.60.0; stdlib 1.27.2, 1.26.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go golang.org/x/net: affected < 0.60.0; fixed in 0.60.0
- Go stdlib: affected < 1.26.9; >= 1.27.0-0, < 1.27.2; fixed in 1.26.9, 1.27.2

## Suggested inspection (read-only)
- Go golang.org/x/net: check the installed version with your package manager.
- Go stdlib: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on golang.org/x/net, stdlib.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GO-2026-6611 (OSV record GO-2026-6611 lists affected ranges: Go stdlib >=0 =1.27.0-0 =0 <0.60.0 (fixed))

Commands are suggestions: review each one before running it.

Loading voting…