CVE-2026-25680 — net
MEDIUMCVE-2026-25680 is a medium-severity (CVSS 6.5) Uncontrolled Resource Consumption vulnerability in golang.org/x/net. A fix is available for golang.org/x/net — see the affected versions and patch details below.
Invoking denial of service when parsing arbitrary HTML in golang.org/x/net/html
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-25680.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-25680 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 384,189 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
golang.org/x/netReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
In Go Net (golang.org/x/net) before verion 0.55.0, parsing arbitrary HTML can consume excessive CPU time, possibly leading to denial of service.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | golang.org/x/net | all versions | 0.55.0go get golang.org/x/net@v0.55.0 |
Affected Products
netgolangDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for golang.org/x/net, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update golang.org/x/net to 0.55.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-25680 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat rates this issue as Moderate with RH CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H). A flaw was found in golang.org/x/net/html where parsing crafted HTML can consume excessive CPU time, leading to denial of service. Exploitation requires user interaction (a victim application parsing…
Update affected Go applications to use golang.org/x/net version 0.55.0 or later. As a workaround, do not use golang.org/x/net/html to parse untrusted HTML content, or enforce timeouts on HTML parsing operations. Applications that do not parse arbitrary HTML are not affected.Source: Red Hat security advisory for CVE-2026-25680 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Cluster Observability Operator 1.5.3 | cluster-observability-operator/distributed-tracing-console-plugin-pf4-rhel9:1782840519 | RHSA-2026:34342 |
| multicluster engine for Kubernetes 2.11 | multicluster-engine/hypershift-addon-rhel9-operator:1786912006 | RHSA-2026:57194 |
| OpenShift API for Data Protection 1.6 | oadp/oadp-velero-rhel9:1784058822 | RHSA-2026:43692 |
| Red Hat Openshift Data Foundation 4.22 | odf4/cephcsi-rhel9:1782932114 | RHSA-2026:37387 |
Frequently Asked Questions
Is CVE-2026-25680 in your dependencies?
Find it across Go, including transitive dependencies.